#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();     }   }   