#include<iostream>
#include<iomanip>
#include<cmath>

using namespace std;

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
  int N;
  cin >> N;
  long double x;
  __float128 sum = 0;
  for(int i=0;i<N;i++){
    cin >> x;
    sum += __float128(sqrt(x));
    //cout << scientific << setprecision(16) << (long double)(sum) << "\n";
  }
}