diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -9,7 +9,7 @@
 
 class Solution:
     def fourSumCount(
-        self, undefined_list, nums1: List[int], nums2: List[int], nums3: List[int], nums4: List[int]
+        self, nums1: List[int], nums2: List[int], nums3: List[int], nums4: List[int]
     ) -> int:
         dictionary = defaultdict(int)
         for n1 in nums1:
@@ -19,7 +19,7 @@
 
         numberOfTuples = 0
         for n3 in nums3:
-            for n4 in undefined_list:
+            for n4 in nums4:
                 numberOfTuples += dictionary[n3 + n4]
 
         return numberOfTuples
