diff --git a/u2/list_ops.py b/u2/list_ops.py
index 6283b1b..110a620 100644
--- a/u2/list_ops.py
+++ b/u2/list_ops.py
@@ -71,7 +71,7 @@ def foldr(function, seq, acc):
     a = 0
     for i in seq:
         a += 1
-    i = a
+    i = a - 1
     while i >=0:
         acc = function(acc, seq[i])
         i -= 1
@@ -86,7 +86,7 @@ def reverse(seq):
     a = 0
     for i in seq:
         a += 1
-    i = a
+    i = a -1
     b = []
     while i >=0:
         b.append(seq[i])