ChessQueens

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ChessQueens
{
    class ChessQueens
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int d = int.Parse(Console.ReadLine());
            int diff = d + 1;
            char[] letters = new char[n];
            int count = 0;

            for(int i = 0; i < n; i++)
            {
                letters[i] = (char)('a' + i);
            }

            for (int x1 = 0; x1 < n; x1++)
            {
                for(int y1 = 0; y1 < n; y1++)
                {
                    for(int x2 = 0; x2 < n; x2++)
                    {
                        for(int y2 = 0; y2 < n; y2++)
                        {
                            bool xMeet = x1 == x2 && Math.Abs(y1 - y2) == diff;
                            bool yMeet = y1 == y2 && Math.Abs(x1 - x2) == diff;
                            bool diagonalMeet = Math.Abs(x1 - x2) == diff && Math.Abs(y1 - y2) == diff;

                            if(xMeet || yMeet || diagonalMeet)
                            {
                                Console.WriteLine("{0}{1} - {2}{3}", letters[x1], y1 + 1, letters[x2], y2 + 1);
                                count++;
                            }
                        }
                    }
                }
            }
            if(count == 0)
            {
                Console.WriteLine("No valid positions");
            }
        }
    }
}