#!/usr/bin/python3
def roman_to_int(roman_string):
    roman_list = roman_string.split()
    nb = 0
    for i in roman_list:
        if i == 'M':
            nb = nb + 1000
        elif i == 'D':
            nb = nb + 500
        elif i == 'C':
            nb = nb + 100
        elif i == 'L':
            nb = nb + 50
        elif i == 'X':
            nb = nb + 10
        elif i == 'V':
            nb = nb + 5
        elif i == 'I':
            nb = nb + 1
