using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter Number");

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

        int ones = x%10; 

        int tens = x%1010;

        int hundred =x/100 %10;

        int thousend =x/1000;

        int loww = ones;

        int bigg;

        if(tens>hundred)

        bigg = tens;    

        else

        bigg =  hundred;

        if(hundred>thousend)

        bigg = bigg;

        else

        bigg = thousend;

        Console.WriteLine("the biggest" +(bigg-loww));

    }

}