#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: huanghengyi
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/