diff --git a/rot.py b/rot.py
index c29100e..b115148 100644
--- a/rot.py
+++ b/rot.py
@@ -1,13 +1,15 @@
 get_bin = lambda x, n: format(x, "b").zfill(n)
 
-rol = lambda val, r_bits, max_bits: (val << r_bits % max_bits) & (2**max_bits - 1) | (
-    (val & (2**max_bits - 1)) >> (max_bits - (r_bits % max_bits))
+mask = lambda max_bits: (1 << max_bits)-1
+
+rol = lambda val, r_bits, max_bits: (val << r_bits % max_bits) & ((1 << max_bits) - 1) | (
+    (val & ((1 << max_bits) - 1)) >> (max_bits - (r_bits % max_bits))
 )
 
 # Rotate right: 0b1001 --> 0b1100
 ror = lambda val, r_bits, max_bits: (
-    (val & (2**max_bits - 1)) >> r_bits % max_bits
-) | (val << (max_bits - (r_bits % max_bits)) & (2**max_bits - 1))
+    (val & ((1 << max_bits) - 1)) >> r_bits % max_bits
+) | (val << (max_bits - (r_bits % max_bits)) & ((1 << max_bits) - 1))
 
 max_bits = 16  # For fun, try 2, 17 or other arbitrary (positive!) values