#include<bits/stdc++.h>
#include<bits/stl_algo.h>
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
using namespace std;
#pragma comment(linker,"\STACK:102400000,102400000")
#define int long long
#define ui unsigned int
#define ull unsigned long long
const int N=1e5+5;
int n,x[N],dp[N];
int cal(int val,int t){
	for (int i=1;i<t;i++)val=(int)sqrt(val);
	return val;
}
bool cmp(int x,int y){return x>y;}
signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	cin>>n;
	for (int i=1;i<=n;i++)cin>>x[i];
	sort(x+1,x+n+1,cmp);
	dp[0]=0;
	for (int i=1;i<=n;i++){
		for (int j=i;j;j--){
			dp[j]=max(dp[j],dp[i-1]+cal(x[i],i));
		}
	}
	cout<<dp[n]<<endl;
	return 0;
}