#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long dot(complex<long long> c1, complex<long long> c2) {
  return imag(c1 * conj(c2));
}
double dot(complex<double> c1, complex<double> c2) {
  return imag(c1 * conj(c2));
}
long long point(complex<long long> c1, complex<long long> c2) {
  return real(c1 * conj(c2));
}
double point(complex<double> c1, complex<double> c2) {
  return real(c1 * conj(c2));
}
void solve() {
  long double n, pi2, alpha, res;
  pi2 = acos(0.0);
  cin >> n;
  alpha = pi2 * (n - 1.0) / n;
  res = tan(alpha);
  cout << res << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t, cases;
  cin >> cases;
  cout << fixed << setprecision(10);
  for (t = 0; t < cases; t++) {
    solve();
  }
}
