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

namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[] args)
        {
            int m, n;
            Console.WriteLine("Введите число m");
            m = int.Parse(Console.ReadLine());
            Console.WriteLine("Введите число m");
            n = int.Parse(Console.ReadLine());

            int[,] mass = new int[m, n];

            int max = 0;
            for (int i = 0; i < m; i++)
            {
                for (int j = 0; j < n; j++)
                {
                    Console.WriteLine("Введите (" + i + "; " + j + ")-ый элемент");
                    mass[i, j] = int.Parse(Console.ReadLine());
                    if (i == 0 && j == 0)
                        max = mass[i, j];
                    else
                    {
                        if (mass[i, j] > max)
                            max = mass[i, j];
                    }
                }
            }

            Console.WriteLine("Maксимальный элемент равен " + max);
            Console.ReadKey();
        }
    }
}