#include <iostream>
#include <iomanip>
using namespace std;

int main(){
	int n,i,j,t;
	int a[100];
	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]){
				t = a[j];
				a[j] = a[j + 1];
				a[j + 1] = t;
			}
		} 
	}
	
	int s = 0;
	for(i = 0;i < 5;i++){
		s += a[i];
	}
	
	double v = s * 1.0 / 5;
	cout<<fixed<<setprecision(1)<<v<<endl;
}
/**************************************************************
	Problem: 1221
	User: admin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/