#include <bits/stdc++.h>   using namespace std;   const long long int N = 2e5 + 5;   void solve() {     long long int n;     cin >> n;     double ans, pi = 3.14159265358979323846;     double rad = (2.0 * sin(pi / (2.0 * (double)n)));     ans = (cos(pi / (4.0 * n))) / sin(pi / (2.0 * (double)n));     cout << fixed << setprecision(15) << ans <<   n ;   }   signed main() {     ios_base::sync_with_stdio(0), cin.tie(NULL), cout.tie(NULL);     long long int t = 1;     cin >> t;     while (t--) {       solve();     }   }   