ROMAN = [(1000, 'M'), (900, 'CM'), (500, 'D'), (400, 'CD'), (100, 'C'), (90, 'XC'), (50, 'L'), (40, 'XL'), (10, 'X'), (9, 'IX'), (5, 'V'), (4, 'IV'), (1, 'I')]

def to_roman(number: int):
    result = ''
    for arabic, roman in ROMAN:
        factor, number = divmod(number, arabic)
        result += roman * factor
    return result