diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -8,7 +8,7 @@
 
 
 class Solution:
-    def palindromePairs(self, words: Arreglo[str]) -> Arreglo[Arreglo[int]]:
+    def palindromePairs(self, words: List[str]) -> List[List[int]]:
         backward, res = {}, []
         for i, word in enumerate(words):
             backward[word[::-1]] = i
