using System;

public class Program

{

    public static void Main()

    {

        romanToDecimal("XLIV");

    }

    public static void romanToDecimal(string romanNumber) 

    {

        int dec = 0;

        int lastNumber = 0;

        string romanNumeral = romanNumber.ToUpper();

             /* operation to be performed on upper cases even if user enters roman values in lower case chars */

        for (int x = romanNumeral.Length - 1; x >= 0 ; x--) {

            char convertToDecimal = romanNumeral[x];

            switch (convertToDecimal) {

                case 'M':

                    dec = processDecimal(1000, lastNumber, dec);

                    lastNumber = 1000;

                    break;

                case 'D':

                    dec = processDecimal(500, lastNumber, dec);

                    lastNumber = 500;

                    break;

                case 'C':

                    dec = processDecimal(100, lastNumber, dec);

                    lastNumber = 100;

                    break;

                case 'L':

                    dec = processDecimal(50, lastNumber, dec);

                    lastNumber = 50;

                    break;

                case 'X':

                    dec = processDecimal(10, lastNumber, dec);

                    lastNumber = 10;

                    break;

                case 'V':

                    dec = processDecimal(5, lastNumber, dec);

                    lastNumber = 5;

                    break;

                case 'I':

                    dec = processDecimal(1, lastNumber, dec);

                    lastNumber = 1;

                    break;

            }

        }

        Console.WriteLine(dec);

    }

    public static int processDecimal(int dec, int lastNumber, int lastDecimal) {

        if (lastNumber > dec) 

        {

            return lastDecimal - dec;

        } else 

        {

            return lastDecimal + dec;

        }

    }

}