#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
void solve() {
  long long n;
  cin >> n;
  n = 2 * n;
  long double dist, ang;
  ang = (360 * 1.0) / (n * 1.0);
  ang = ang / 2.0;
  long double rad = ang / 180.0;
  rad = rad * pi;
  dist = tan(rad);
  dist = 1.0 / dist;
  cout << fixed << setprecision(10) << dist;
  cout << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long t = 1;
  cin >> t;
  while (t--) solve();
}
