#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,d,m=0;
	double s;
	cin>>n;
	int a[n];
	for(int i=0;i<n;i++){
		cin>>a[i];
	}
	d=a[0];
	for(int i=0;i<=n+1;i++){
		for(int i=1;i<n;i++){
		if(d<a[i]){
			swap(a[i-1],a[i]);
		}	
	}
	}
	for(int i=0;i<5;i++){
		m+=a[i];
	}
	s=m/5.00;
	printf("%.1f",s);
}

/**************************************************************
	Problem: 1221
	User: wuzhijing
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/