def roman_main(args):
    """Convert first arg to roman numeral if <= 5000 else :return: second arg."""
    num = int(float(args.get('1')))
 
    # Return a message for numbers too big to be expressed in Roman numerals.
    if 0 > num or num >= 5000:
        return args.get('2', 'N/A')
 
    def toRoman(n, romanNumeralMap):
        """convert integer to Roman numeral"""
        result = ""
        for integer, numeral in romanNumeralMap:
            while n >= integer:
                result += numeral
                n -= integer
        return result

    # Find the Roman numerals for numbers 4999 or less.
    smallRomans = (
        (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") 
    )
    return toRoman(num, smallRomans)