Given a number in Roman numeral format, convert it to Arabic.
The values of Roman numerals are as follows:
{
"M": 1000,
"D": 500,
"C": 100,
"L": 50,
"X": 10,
"V": 5,
"I": 1
}In addition, note that the Roman numeral system uses subtractive notation for numbers such as IV and XL.
For the input "XIV", for instance, you should return 14.
More examples
Input: s = "III" Output: 3
Input: s = "LVIII" Output: 58
Input: s = "MCMXCIV" Output: 1994