#include<bits/stdc++.h>
using namespace std;
int main(){
	int a[110]={0},n,i,h=1;
	float j;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	for(h=1;h<n;h++){
		for(i=0;i<n-h;i++){
			if(a[i]<a[i+1]){
			    swap(a[i],a[i+1]);	
			}
		}
	}
	j=1.0*(a[0]+a[1]+a[2]+a[3]+a[4])/5;
	printf("%.1f",j); 
}

/**************************************************************
	Problem: 1221
	User: wngjinming
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/