using System;

​

public class Program

{

    public static void Main()

    {

        string[] romanNumbers = new[]{"IIXIIV", "MMLXXIV"};

        foreach (string number in romanNumbers)

        {

            int decimalNumber = FromRoman(number);

            Console.WriteLine("{0}: {1}", number, decimalNumber);

        }

    }

​

    // returns the value for a roman literal

    private static int romanValue(int index)

    {

        int basefactor = ((index % 2) * 4 + 1); // either 1 or 5...

        // ...multiplied with the exponentation of 10, if the literal is `x` or higher

        return index > 1 ? (int)(basefactor * System.Math.Pow(10.0, index / 2)) : basefactor;

    }

​

    public static int FromRoman(string roman)

    {

        roman = roman.ToLower();

        string literals = "mdclxvi";

        int value = 0, index = 0;

        foreach (char literal in literals)

        {

            value = romanValue(literals.Length - literals.IndexOf(literal) - 1);

            index = roman.IndexOf(literal);

            if (index > -1)

                return FromRoman(roman.Substring(index + 1)) + (index > 0 ? value - FromRoman(roman.Substring(0, index)) : value);

        }

​

        return 0;

    }

}