#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,m=0,a[100],i,j;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>a[i];
	}
	for(i=1;i<=n-1;i++){
		for(j=1;j<=n-i;j++){
			if(a[j]>a[j-1])
				swap(a[j],a[j-1]); 
		}		
	}
	for(i=0;i<5;i++){
		m+=a[i];
	}
	printf("%.1f",m/5.0);
	return 0;
}
/**************************************************************
	Problem: 1221
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/