diff --git a/3518/solution.cpp b/3518/solution.cpp
index 3a48c63..efb16eb 100644
--- a/3518/solution.cpp
+++ b/3518/solution.cpp
@@ -34,7 +34,7 @@ public:
     }
 
     auto it = permutations.begin();
-    advance(it, k);
+    advance(it, k - 1);
 
     string mirroredHalf = *it;
     reverse(mirroredHalf);