diff --git a/td_debug.ts b/td_debug.ts
index 46252a863443502e2fcdb45b22478c72d0f8cff2..2a8cccc9c3eca96700df93f1e7646d09ed18bed6 100644
--- a/td_debug.ts
+++ b/td_debug.ts
@@ -68,7 +68,18 @@
 //   if( x = 0 || y = 0) return x*y;
 //   else if( x = 0 && y = 0) return - x*y;
 //   else return x * y;
-
 // }
 
 // console.log(deb7(5, -3));
+
+//exercice 8
+
+function deb8(n: number): number {
+  if (n === 0) {
+    return 1;
+  }
+  return n * deb8(n - 1);
+}
+
+const n = 5;
+console.log(deb8(n));