import argparse


def main():
    parser = argparse.ArgumentParser(description='Reverse input number in bin format')
    parser.add_argument('number', help='decimal number', type=int)
    args = parser.parse_args()

    # check number range
    if not(1 <= args.number <= 1000000000):
        raise ValueError('number should be from 1 to 1000000000')

    bin_str = bin(args.number)
    # remove first '0b' marker and reverse order
    reverted = bin_str[2:][::-1]
    # convert back to int
    result1 = int(reverted, 2)
    print(result1)

    # or one-liner
    result2 = int(str(bin(args.number)[2:][::-1]), 2)
    print(result2)


if __name__ == '__main__':
    main()