def FYinv(bits):
    for i in range(63, (- 1), (- 1)):
        j = (((i ** 3) % 67) % 64)
        (bits[i], bits[j]) = (bits[j], bits[i])
def FYinv(bits):
    for i in range(63, (- 1), (- 1)):
        j = (((i ** 3) % 67) % 64)
        (bits[i], bits[j]) = (bits[j], bits[i])