diff --git a/utils/utils.py b/utils/utils.py
index d4cf947..44ba6a1 100644
--- a/utils/utils.py
+++ b/utils/utils.py
@@ -2,19 +2,19 @@ import numpy as np
 
 # for multiple predictions, modify from `learn_add.py`
 def flatten(l):
-    return [item for sublist in l for item in _flatten(sublist)] if isinstance(l, list) else [l]
+    return [item for sublist in l for item in flatten(sublist)] if isinstance(l, list) else [l]
     
 # for multiple predictions, modify from `learn_add.py`
-def reform_ids(flatten_pred_res, save_pred_res):
+def reform_idx(flatten_pred_res, save_pred_res):
     re = []
     i = 0
     for e in save_pred_res:
         j = 0
-        ids = []
+        idx = []
         while j < len(e):
-            ids.append(flatten_pred_res[i + j])
+            idx.append(flatten_pred_res[i + j])
             j += 1
-        re.append(ids)
+        re.append(idx)
         i = i + j
     return re