package com.javarush.task.task04.task0419;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
/*
Максимум четырех чисел
*/

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String n1 = reader.readLine();
        String n2 = reader.readLine();
        String n3 = reader.readLine();
        String n4 = reader.readLine();
        int a = Integer.parseInt(n1);
        int b = Integer.parseInt(n2);
        int c = Integer.parseInt(n1);
        int d = Integer.parseInt(n2);

        int maxAB;

        if(a >= b){
            maxAB = a;
        } else maxAB = b;

        int maxCD;

        if(c >= d){
            maxCD = c;
        } else maxCD = d;

        if(maxAB >= maxCD){
            System.out.println(maxAB);
        } else System.out.println(maxCD);

    }
}