using System;

public class  GFG {

​

        public virtual int value(char r)

    {

        if (r == 'I')

            return 1;

        if (r == 'V')

            return 5;

        if (r == 'X')

            return 10;

        if (r == 'L')

            return 50;

        if (r == 'C')

            return 100;

        if (r == 'D')

            return 500;

        if (r == 'M')

            return 1000;

        return -1;

    }

    // Finds decimal value of a

    // given roman numeral

    public virtual int romanToDecimal(string str)

    {

        // Initialize result

        int res = 0;

        for (int i = 0; i < str.Length; i++) {

            // Getting value of symbol s[i]

            int s1 = value(str[i]);

            // Getting value of symbol s[i+1]

            if (i + 1 < str.Length) {

                int s2 = value(str[i + 1]);

                // Comparing both values

                if (s1 >= s2) {

                    // Value of current symbol is greater

                    // or equalto the next symbol

                    res = res + s1;

                }

                else {

                    res = res + s2 - s1;

                    i++; // Value of current symbol is

                    // less than the next symbol

                }

            }

            else {

                res = res + s1;

                i++;

            }

        }

        return res;

    }

    // Driver Code

    public static void Main(string[] args)

    {

        GFG ob = new GFG();

        // Considering inputs given are valid

        string str = "V";

        Console.WriteLine("Integer form of Roman Numeral"

                          + " is "

                          + ob.romanToDecimal(str));

    }

}

// This code is contributed by Shrikant13

​