diff --git a/models/gwcnet.py b/models/gwcnet.py
index 4746807..adc4f29 100644
--- a/models/gwcnet.py
+++ b/models/gwcnet.py
@@ -5,6 +5,7 @@ import torch.utils.data
 from torch.autograd import Variable
 import torch.nn.functional as F
 from models.submodule import *
+import math
 
 
 class feature_extraction(nn.Module):