diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -11,6 +11,6 @@
     res[B[i] - 1] = 1
 
 if res.count(0) == 1:
-    print(A[res.index(0)])
+    print(res.index(0) + 1)
 else:
     print(-1)
