#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c,d;
	cin>>a>>b>>c>>d;
	if(a>b&&a>c&&a>d) cout<<a; 
	if(b>a&&b>c&&b>d) cout<<b; 
	if(c>b&&c>a&&c>d) cout<<c; 
	if(d>c&&d>a&&d>b) cout<<d; 
	return 0;
}

/**************************************************************
	Problem: 1305
	User: lvrenxiang
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/