diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -14,7 +14,7 @@
 flg = 1
 if abs(xy - yx) >= 2:
     flg = 0
-if xx > 0 and xx > 0 and yx == 0 and xy == 0:
+if xx > 0 and yy > 0 and yx == 0 and xy == 0:
     flg = 0
 
 print("Yes" if flg else "No")
