def bin_exp_mod(a, n, b):
# mod b
assert not (b == 0), "This cannot accept modulo that is == 0"
if n == 0:
return 1
if n % 2 == 1:
return (bin_exp_mod(a, n - 1, b) * a) % b
r = bin_exp_mod(a, n / 2, b)
return (r * r) % b
if __name__ == "__main__":
try:
BASE = int(input("Enter Base : ").strip())
POWER = int(input("Enter Power : ").strip())
MODULO = int(input("Enter Modulo : ").strip())
except ValueError:
print("Invalid literal for integer")
print(bin_exp_mod(BASE, POWER, MODULO))
