#include <iostream>
#include <cmath>
#include <climits>

using namespace std;

int main(){
    int n;
    cin >> n;
    double sqrtOfHeight = 0;
    for(int i = 0; i < n; i++){
        int square;
        cin >> square;
        sqrtOfHeight +=  sqrt(square);
    }
    cout << (unsigned long long) (1000 * sqrtOfHeight * sqrtOfHeight);
    return 0;
}