diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -5,20 +5,23 @@
 import bisect
 import itertools
 import functools
+
+
 class Solution:
     def restoreArray(self, adjacentPairs: List[List[int]]) -> List[int]:
         graph = {}
-        for u, v in adjacentPairs: 
+        for u, v in adjacentPairs:
             graph.setdefault(u, []).append(v)
             graph.setdefault(v, []).append(u)
-        
+
         ans = []
         seen = set()
         stack = [next(x for x in graph if len(graph[x]) == 1)]
-        while stack 
+        while stack:
             n = stack.pop()
             ans.append(n)
             seen.add(n)
-            for nn in graph[n]: 
-                if nn not in seen: stack.append(nn = 
+            for nn in graph[n]:
+                if nn not in seen:
+                    stack.append(nn)
         return ans
