#include<bits/stdc++.h> 
using namespace std;
int main(){
    int a1,a2,a3,a4;
    cin>>a1>>a2>>a3>>a4;
    if(a1>a2&&a1>a3&&a1>a4){
        cout<<a1;
    }
    if(a2>a1&&a2>a3&&a2>a4){
        cout<<a2;
    }
    if(a3>a1&&a3>a2&&a3>a4){
        cout<<a3;
    }
    if(a4>a1&&a4>a2&&a4>a3){
        cout<<a4;
    }
	 
} 
/**************************************************************
	Problem: 1305
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/