#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;
else if((b>a)&&(b>c)&&(b>d))cout<<b;
	else if((c>a)&&(c>b)&&(c>d))cout<<c;
		else if((d>a)&&(d>c)&&(d>b))cout<<d;
return 0;

}

/**************************************************************
	Problem: 1305
	User: sf751616
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/