#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1);
double f(double x, double N){
  return exp(cos(x / N));
}
int main(){
  cout << fixed << setprecision(20);
  vector<double> A(1001, 0);
  for (int i = 1; i <= 1000; i++){
    double mx = 1 / (exp(1) * PI * PI);
    for (int j = 0; j < 1000; j++){
      double l = mx * j / 1000;
      double r = mx * (j + 1) / 1000;
      double m = (l + r) / 2;
      A[i] += (f(l, i) + f(m, i) * 4 + f(r, i)) / 6;
    }
    A[i] *= mx;
    A[i] /= 1000;
  }
  int T;
  cin >> T;
  for (int i = 0; i < T; i++){
    int N;
    cin >> N;
    cout << A[min(N, 1000)] << "\n";
  }
}