diff --git a/training/dataset/abstract_dataset.py b/training/dataset/abstract_dataset.py
index a9c2069..89b855d 100644
--- a/training/dataset/abstract_dataset.py
+++ b/training/dataset/abstract_dataset.py
@@ -201,9 +201,9 @@ def collect_img_and_label_for_one_dataset(self, dataset_name: str):
                 frame_paths = video_info['frames']
                 # sorted video path to the lists
                 if '\\' in frame_paths[0]:
-                    frame_paths = sorted(frame_paths, key=lambda x: int(frame_paths[0].split('\\')[-1].split('.')[0]))
+                    frame_paths = sorted(frame_paths, key=lambda x: int(x.split('\\')[-1].split('.')[0]))
                 else:
-                    frame_paths = sorted(frame_paths, key=lambda x: int(frame_paths[0].split('/')[-1].split('.')[0]))
+                    frame_paths = sorted(frame_paths, key=lambda x: int(x.split('/')[-1].split('.')[0]))
 
                 # Consider the case when the actual number of frames (e.g., 270) is larger than the specified (i.e., self.frame_num=32)
                 # In this case, we select self.frame_num frames from the original 270 frames
@@ -599,4 +599,4 @@ def __len__(self):
         # print(iteration)
         ...
         # if iteration > 10:
-        #     break
\ No newline at end of file
+        #     break