numbers_arb_rim = dict(zip((1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1),
    'M     CM   D    CD   C    XC  L   XL  X   IX V  IV I'.split()))


def arabic2rim_nums(n: int) -> str:
    global numbers_arb_rim

    result = ''
    for arabic, roman in numbers_arb_rim.items():
        result += n // arabic * roman
        n %= arabic
    return result


def rim2arabic_nums(num_rim: str) -> int:
    global numbers_arb_rim

    num_arb = 0
    for num_value, num_name in numbers_arb_rim.items():
        num_arb += num_rim.count(num_name) * num_value
        num_rim = num_rim.replace(num_name, '')

    return num_arb