#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: wangyiyang
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/