#include<bits/stdc++.h>
using namespace std;
int main(){
	int i,j,n,a[105]={};
	float h,z=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++){
		z=z+a[i];
	}
	h=z/5.0;
	printf("%.1f",h);
}
/**************************************************************
	Problem: 1221
	User: zengyixuan
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/