#include <iostream>
#include <algorithm>
using namespace std;
long long n,a[300005],s;
double maxn;
int main(){
	cin>>n; 
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	sort(a+1,a+1+n);
	for (int i=n;i>=1;i--){
		s+=a[i]; 
		maxn=max(maxn,s*1.0/(n-i+1)*s);
	}
	cout<<maxn;
	return 0;
}