#!/usr/bin/env python3

import sys

MODULUS = 1 << 24
FACTOR = 5
BIAS = 0x456789
FACTOR_INVERSE = pow(FACTOR, -1, MODULUS)


def pack(value):
    number = int(value, 16)
    result = (number * FACTOR + BIAS) % MODULUS
    return f"{result:06x}"


def unpack(value):
    number = int(value, 16)
    result = ((number - BIAS) * FACTOR_INVERSE) % MODULUS
    return f"{result:06x}"


def main():
    if len(sys.argv) != 3:
        raise SystemExit(2)

    operation = sys.argv[1]
    value = sys.argv[2].lower()

    if len(value) != 6:
        raise SystemExit(2)

    if operation == "pack":
        print(pack(value))
    elif operation == "unpack":
        print(unpack(value))
    else:
        raise SystemExit(2)


if __name__ == "__main__":
    main()