package com.javarush.task.task04.task0419;

/*
Максимум четырех чисел
*/

import java.io.*;

public class Solution {
    public static void main(String[] args) throws Exception {
        //напишите тут ваш код
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String s1 = reader.readLine();
        String s2 = reader.readLine();
        String s3 = reader.readLine();
        String s4 = reader.readLine();
        int a = Integer.parseInt(s1);
        int b = Integer.parseInt(s2);
        int c = Integer.parseInt(s3);
        int d = Integer.parseInt(s4);
        int max = a;
        if (max < b)
            max = b;
        else if (max < c)
            max = c;
        else if (max < d)
            max = d;
        System.out.println(max);
    }
}