#include <bits/stdc++.h>
using namespace std;
const long long N = 200005, INF = 2000000000000000000;
long long power(long long a, long long b, long long p) {
  if (a == 0) return 0;
  long long res = 1;
  a %= p;
  while (b > 0) {
    if (b & 1) res = (res * a) % p;
    b >>= 1;
    a = (a * a) % p;
  }
  return res;
}
int32_t main() {
  std::ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cout.precision(std::numeric_limits<double>::max_digits10);
  ;
  long long t;
  cin >> t;
  while (t--) {
    long double n, pi = 3.1415926535897932;
    cin >> n;
    n *= 2.0;
    long double v = pi / n;
    cout << 1.0 / tan(v) << "\n";
  }
}
