diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -26,7 +26,7 @@
         OI[i] = OI[i - 1]
 
 ans = set()
-for i in range(N):
+for i in range(N - 1):
     ans.add((OI[-1] - OI[i]) + (IO[i]))
     ans.add(IO[-1] - IO[i] + (OI[i]))
 
