using System.CodeDom.Compiler;
using System.Numerics;
using System.Security.Cryptography.X509Certificates;

namespace projectEuler {
    //
    class question15 {
        question15(){

        }

        public static BigInteger Solve(int x, int y){
            List<List<BigInteger>> grid = new List<List<BigInteger>>();
            //initialize grid
            for(int width = 0; width < x; width++){
                grid.Add(new List<BigInteger>());
                string row = "";
                for(int height = 0; height < y; height++){
                    grid[width].Add(0);
                    row += " 0";
                }
                Console.WriteLine(row);
            }

            
            grid[0][0] = 1;
            for(int width = 0; width < x; width++) {
                string row = "";
                for(int height = 0; height < x ; height++){
                    if(grid[width][height] == 1){
                        continue;
                    }
                    BigInteger top = 0;
                    BigInteger left = 0;
                    if(width - 1 >= 0)
                    {
                        left = grid[width-1][height];
                    }
                    if(height - 1 >= 0){
                        top = grid[width][height-1];
                    }
                    if(top == 0 || left == 0) {
                        row += " 1";
                        grid[width][height] = 1;
                    } else {
                        row += " " + (top + left).ToString();
                        grid[width][height] = top + left;
                    }

                }
                Console.WriteLine(row);
            }
            return grid[x-1][y-1];


        }
        
    }
}