diff --git a/models.py b/models.py
index ccb1ce9..f0b6d18 100644
--- a/models.py
+++ b/models.py
@@ -1,5 +1,5 @@
 import torch
-from torch import nn
+from torch import nn, einsum
 import torch.nn.functional as F
 import numpy as np
 from functools import partial