using System;

public class Program

{

    public static void Main()

    {

        int rowX = 20;

        int colY = 20;

        int numberofproduct = 4;

        decimal sumofprod = sumofproductfromgridresult(colY,rowX,numberofproduct);

        //Console.Writeline("sum of 4 products in 20*20 grid: " + sumofprod.ToString());

        Console.WriteLine("sum of 4 products in 20*20 grid: " + sumofprod.ToString());

    }

    public static decimal sumofproductfromgridresult(int rowX, int colY, int numberofproduct)

    {

        decimal sumofproductfromgrid=0;

        int[,] temparray = new int[,]{ 

            { 08, 02, 22, 97, 38, 15, 00, 40, 00, 75, 04, 05, 07, 78, 52, 12, 50, 77, 91, 08}, 

            { 49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 04, 56, 62, 00},

            { 81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 03, 49, 13, 36, 65},

            { 52, 70, 95, 23, 04, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91},

            { 22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},

            { 24, 47, 32, 60, 99, 03, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},

            { 32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},

            { 67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63, 08, 40, 91, 66, 49, 94, 21},

            { 24, 55, 58, 05, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},

            { 21, 36, 23, 09, 75, 00, 76, 44, 20, 45, 35, 14, 00, 61, 33, 97, 34, 31, 33, 95},

            { 78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 03, 80, 04, 62, 16, 14, 09, 53, 56, 92},

            { 16, 39, 05, 42, 96, 35, 31, 47, 55, 58, 88, 24, 00, 17, 54, 24, 36, 29, 85, 57},

            { 86, 56, 00, 48, 35, 71, 89, 07, 05, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},

            { 19, 80, 81, 68, 05, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40},

            { 04, 52, 08, 83, 97, 35, 99, 16, 07, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},

            { 88, 36, 68, 87, 57, 62, 20, 72, 03, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},

            { 04, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 08, 46, 29, 32, 40, 62, 76, 36},

            { 20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 04, 36, 16},

            { 20, 73, 35, 29, 78, 31, 90, 01, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 05, 54},

            { 01, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48} }; 

                //Console.WriteLine(temparray.GetLength(0));

                //Console.WriteLine(temparray.GetLength(1));

        for(int col =0; col < temparray.GetLength(0); col++){

            for(int row =0; row < temparray.GetLength(1);row++){

                //Console.WriteLine(temparray[col, row]);

                decimal tempprod;

                //check vertically

                if(row< temparray.GetLength(0) - numberofproduct){

                    tempprod = temparray[col,row];

                    for(int i = 1; i< numberofproduct ; i++){

                        //Console.WriteLine(temparray[col, row]);

                        tempprod *= temparray[col, row+ i];

                    }

                    //Console.WriteLine(tempprod);

                    sumofproductfromgrid = Math.Max(sumofproductfromgrid, tempprod);

                }

                //check horizontally

                if (col < temparray.GetLength(1) - numberofproduct){

                    tempprod = temparray[col,row];

                    for (int i = 1 ; i < numberofproduct;i++){

                        tempprod *= temparray[col+i, row];

                    }

                    //Console.WriteLine(tempprod);

                    sumofproductfromgrid = Math.Max(sumofproductfromgrid, tempprod);

                }

                //check diagonally upwords/forward

                if ((col < temparray.GetLength(0) - numberofproduct) && (row >= numberofproduct)){

                    tempprod = temparray[col,row];

                    for(int i = 1 ; i<= numberofproduct; i++){

                        tempprod *= temparray[col + i, row -i];

                    }

                    //Console.WriteLine(tempprod);

                    sumofproductfromgrid = Math.Max(sumofproductfromgrid, tempprod);

                }

                //check diagonally downwords/ forward

                if ((row < temparray.GetLength(0) - numberofproduct) && (col < temparray.GetLength(1) -  numberofproduct)){

                    tempprod = temparray[col,row];

                    for(int i = 1 ; i<= numberofproduct; i++){

                        tempprod *= temparray[col+i,row +i];

                    }

                    //Console.WriteLine(tempprod);

                    sumofproductfromgrid = Math.Max(sumofproductfromgrid, tempprod);

                }

            }

        }

        return sumofproductfromgrid;

    }

}