#include<stdio.h>
void main()
{
	int a,b,c,d,t;
	scanf("%d%d%d%d",&a,&b,&c,&d);
	if(a>b){
		t=a;
		a=b;
		b=t;
	}
	if(b>c){
		t=b;
		b=c;
		c=t;
	}
	if(c>d){
		t=c;
		c=d;
		d=t;
	} 
	if(a>b){
		t=a;
		a=b;
		b=t;
	}
	if(b>c){
		t=b;
		b=c;
		c=t;
	}
	if(c>d){
		t=c;
		c=d;
		d=t;
	} 
	if(a>b){
		t=a;
		a=b;
		b=t;
	}
	if(b>c){
		t=b;
		b=c;
		c=t;
	}
	printf("%d",d);
} 
/**************************************************************
	Problem: 1305
	User: admin
	Language: C
	Result: Accepted
	Time:17 ms
	Memory:1144 kb
****************************************************************/