from urandom import *


def randrange(start, stop=None):
    if stop is None:
        stop = start
        start = 0
    upper = stop - start
    bits = 0
    pwr2 = 1
    while upper > pwr2:
        pwr2 <<= 1
        bits += 1
    while True:
        r = getrandbits(bits)
        if r < upper:
            break
    return r + start