Roman to Integer

Easy

Description

Roman numerals use seven symbols: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000.

Symbols are normally written from the biggest to the smallest, and their values are added. But when a smaller symbol comes right before a bigger one, its value is taken away instead. This happens in six cases: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900).

Given a Roman numeral s, return its value as an integer.

Examples

Example 1:

Input: s = "XIV"
Output: 14
Explanation: X = 10 and IV = 4.

Example 2:

Input: s = "MMXXIV"
Output: 2024
Explanation: MM = 2000, XX = 20 and IV = 4.

Example 3:

Input: s = "CMXCIX"
Output: 999
Explanation: CM = 900, XC = 90 and IX = 9.

Hash Table
Math
String

Constraints

s uses only these characters: I, V, X, L, C, D, M.
1 <= s.length <= 15
s is a valid Roman numeral for a number from 1 to 3999.

Examples

3 shown

Example 1

Input

"XIV"

Output

Example 2

Input

"MMXXIV"

Output

Example 3

Input

"CMXCIX"

Output

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