diff --git a/applications/ColossalChat/coati/reasoner/guided_search/mcts.py b/applications/ColossalChat/coati/reasoner/guided_search/mcts.py
index 438d0ed5f..100335ba9 100644
--- a/applications/ColossalChat/coati/reasoner/guided_search/mcts.py
+++ b/applications/ColossalChat/coati/reasoner/guided_search/mcts.py
@@ -120,14 +120,14 @@ class MCTS(BaseModel):
             self.back_propagation(child)
 
         return self.get_best_answer()
-    
+
     def _iter_nodes(self):
         to_visit = deque([self.root])
         while to_visit:
             current_node = to_visit.popleft()
             yield current_node
             to_visit.extend(current_node.children)
-    
+
     def get_best_answer(self):
         best_node = max(self._iter_nodes(), key=lambda node: node.Q, default=self.root)
         return best_node.answer