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

/**************************************************************
	Problem: 1708
	User: zhengzihao3
	Language: C++
	Result: Accepted
	Time:19 ms
	Memory:2072 kb
****************************************************************/