using System;

public class Program

{

    public static void Main()

    {

          int[,] A;

​

        int N, M;

        Console.WriteLine("Nhap so dong");

        N = int.Parse(Console.ReadLine());

​

        Console.WriteLine("Nhap so cot");

        M = int.Parse(Console.ReadLine());

​

        A = new int[N,M];

​

        for (int i = 0; i<A.GetLength(0); i++)

        {

            for (int j = 0; j < A.GetLength(1); j++)

            {

                Console.WriteLine($"Nhap A[{i}][{j}]: ");

                A[i, j] = int.Parse(Console.ReadLine());

            }

        }

​

​

        TinhTrungBinhCongCacPhanTuChan(A);

    }

     static int TinhTrungBinhCongCacPhanTuChan(int[,] A)

        {

            int sum = 0, count = 0;

            for(int i=0; i<A.GetLength(0); i ++)

            {

                for(int j=0; j<A.GetLength(1); j++)

                {

                    if ( A[i,j] % 2 == 0)

                    {

                        sum += A[i, j];

                        count += 1;

                    }

                }

            }

​

            if (count > 0)

            {

                return (sum / count);

            }

​

            return -1;

        }

}

​