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

/**************************************************************
	Problem: 1305
	User: ccf
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/