#include <bits/stdc++.h>
using namespace std;
int main(){
	int a[100],i,j,n,x,y;;
	float h=0;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	for(i=1;i<n;i++){
        for(j=0;j<n-i;j++){
            if(a[j]<a[j+1]){
                swap(a[j],a[j+1]);
            }
        }
    }
	for(i=0;i<5;i++){
		h=h+a[i];
	}
	h=h/5;
	printf("%.1f",h);
}
/**************************************************************
	Problem: 1221
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/