package com.javarush.task.task05.task0532;

import java.io.*;

/*
Задача по алгоритмам
*/

public class Solution {
    public static void main(String[] args) throws Exception {
        int max = 0;
        int s = 0;

        while (true) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int first = Integer.parseInt(reader.readLine());


            if (first > 0) {
                if (first > max)
                    max = first;
                    else s = first;
            }


        }
        System.out.println(max);
    }
}