using System;

public class Program

{

    public static int MaxDigit(int num)

        {

            int x = num % 10 , max = 0 ;

            if (num < 10 && num > x)

            {

                max = num;

            }

            if (x > max)

            {

                max = x;

                MaxDigit(num / 10);

​

​

            }

            return max;

        }

}