#include<iostream>
#include<cmath>
#include<vector>
#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin >> n;
	long a[n];
	for(int i = 0;i < n;i++)
	{
		cin >> a[i];
	}
	for(int i = 0;i < n-1;i++)
	{
		bool f = true;
		for(int j = 0;j < n-i-1;j++)
		{
			if(a[j] < a[j+1])
			{
				swap(a[j],a[j+1]); 
				f = false;
			}
		}
		if(f)
		{
			break;
		}
	}
	long re = 0;
	for(int i = 0;i < n;i++)
	{
		re += (long)pow(a[i],pow(0.5,i)); 
	}
	cout << re;
}