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

/**************************************************************
	Problem: 1221
	User: zouliangyin
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/