diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -14,7 +14,7 @@
         l, r = 0, k - 1
         res = float("inf")
         while r < len(nums):
-            res = Math.min(res, nums[r] - nums[l])
+            res = min(res, nums[r] - nums[l])
             r += 1
             l += 1
         return res
