using System;

public class Program

{

    public static int bigger;

    public static void Biggest(int a, int b)

    {

        if(a>b)

        bigger =a;

        else 

        bigger= b;

    }

    public static void Main()

    {

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

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

        Biggest(m,n);

        while(m!=0)

        {

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

            Biggest(bigger,m);

        }

        Console.WriteLine(bigger);

    }

}