diff --git a/13/13.py b/13/13.py
index a39a872..07a35ef 100755
--- a/13/13.py
+++ b/13/13.py
@@ -61,7 +61,7 @@ def fold_horizontally(g, fold_y):
                 g[new_y][x] = 1
 
     # cut the other half of the grid
-    for i in range(fold_y+1):
+    for _ in range(fold_y+1):
         g.pop()