using System;

public class Program

{

    public static void Main()

    {

        int[,] array = {

            {12, 23, 45, 67}, 

            {78, 56, 89, 90}, 

            {34, 65, 77, 29}, 

            {19, 31, 73, 81}

        };

        int max = array[0, 0];

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

        {

            for (int x = 0; x < array.GetLength(1); x++)

            {

                if (array[i, x] > max)

                {

                    max = array[i, x]; 

                }

            }

        }

        Console.WriteLine(" Maximum value : " + max);

    }

}