Only render fixed number of mermaid blocks

3 files changed, 48 insertions, 1 deletions

diff --git a/app/assets/javascripts/behaviors/markdown/render_mermaid.js b/app/assets/javascripts/behaviors/markdown/render_mermaid.js
index 27708504791..c3e2c09f1d5 100644
--- a/app/assets/javascripts/behaviors/markdown/render_mermaid.js
+++ b/app/assets/javascripts/behaviors/markdown/render_mermaid.js
@@ -36,6 +36,8 @@ export default function renderMermaid($els) {
         securityLevel: 'strict',
       });
 
+      let renderedChars = 0;
+
       $els.each((i, el) => {
         // Mermaid doesn't like `<br />` tags, so collapse all like tags into `<br>`, which is parsed correctly.
         const source = el.textContent.replace(/<br\s*\/>/g, '<br>');
@@ -45,7 +47,7 @@ export default function renderMermaid($els) {
          * prevent mermaidjs from hanging up the entire thread and
          * causing a DoS.
          */
-        if (source && source.length > MAX_CHAR_LIMIT) {
+        if ((source && source.length > MAX_CHAR_LIMIT) || renderedChars > MAX_CHAR_LIMIT) {
           el.textContent = sprintf(
             __(
               'Cannot render the image. Maximum character count (%{charLimit}) has been exceeded.',
@@ -55,6 +57,7 @@ export default function renderMermaid($els) {
           return;
         }
 
+        renderedChars += source.length;
         // Remove any extra spans added by the backend syntax highlighting.
         Object.assign(el, { textContent: source });
 
diff --git a/changelogs/unreleased/security-mermaid-block.yml b/changelogs/unreleased/security-mermaid-block.yml
new file mode 100644
index 00000000000..993e8cfec08
--- /dev/null
+++ b/changelogs/unreleased/security-mermaid-block.yml
@@ -0,0 +1,5 @@
+---
+title: Only render fixed number of mermaid blocks
+merge_request:
+author:
+type: security
diff --git a/spec/features/markdown/mermaid_spec.rb b/spec/features/markdown/mermaid_spec.rb
index aaaceebc216..b2a31ff2275 100644
--- a/spec/features/markdown/mermaid_spec.rb
+++ b/spec/features/markdown/mermaid_spec.rb
@@ -41,4 +41,43 @@ describe 'Mermaid rendering', :js do
     expected = '<text><tspan xml:space="preserve" dy="1em" x="1">Line 1</tspan><tspan xml:space="preserve" dy="1em" x="1">Line 2</tspan></text>'
     expect(page.html.scan(expected).count).to be(4)
   end
+
+  it 'renders only 2 Mermaid blocks and ', :js do
+    description = <<~MERMAID
+    ```mermaid
+    graph LR
+    A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;
+    ```
+    ```mermaid
+    graph LR
+    A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;
+    ```
+    ```mermaid
+    graph LR
+    A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;
+    ```
+    ```mermaid
+    graph LR
+    A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;
+    ```
+    ```mermaid
+    graph LR
+    A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;
+    ```
+    ```mermaid
+    graph LR
+    A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;B-->A;A-->B;
+    ```
+    MERMAID
+
+    project = create(:project, :public)
+    issue = create(:issue, project: project, description: description)
+
+    visit project_issue_path(project, issue)
+
+    page.within('.description') do
+      expect(page).to have_selector('svg')
+      expect(page).to have_selector('pre.mermaid')
+    end
+  end
 end