Chessboard Game

using System;

namespace ChessboardGame
{
    class Program
    {
        public static void Main(string[] args)
        {
            int size = int.Parse(Console.ReadLine());
            string text = Console.ReadLine();

            int sizeOfChessboard = (size * size);
            int blackTeam = 0;
            int whiteTeam = 0;
            int advantagePoints = 0;

            for (int currentLetter = 0; currentLetter < sizeOfChessboard; currentLetter++)
            {
                if (currentLetter < text.Length)
                {
                    char letter = text[currentLetter];

                    //black team turn
                    if (currentLetter % 2 == 0)
                    {
                        if ((letter >= 'a' && letter <= 'z') || (letter >= '0' && letter <= '9'))
                        {
                            blackTeam += (int)letter;
                        }
                        else if (letter >= 'A' && letter <= 'Z')
                        {
                            whiteTeam += (int)letter;
                        }
                    }
                    //white team turn
                    else
                    {
                        if ((letter >= 'a' && letter <= 'z') || (letter >= '0' && letter <= '9'))
                        {
                            whiteTeam += (int)letter;
                        }
                        else if (letter >= 'A' && letter <= 'Z')
                        {
                            blackTeam += (int)letter;
                        }
                    }
                }
            }

            if (blackTeam > whiteTeam)
            {
                advantagePoints = (blackTeam - whiteTeam);

                Console.WriteLine("The winner is: black team");
                Console.WriteLine(advantagePoints);
            }
            else if (blackTeam < whiteTeam)
            {
                advantagePoints = (whiteTeam - blackTeam);

                Console.WriteLine("The winner is: black team");
                Console.WriteLine(advantagePoints);
            }
            else
            {
                Console.WriteLine("Equal result: {0}", blackTeam);
            }
                    }
    }
}