#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <set>
#include <cstdlib>
#include <queue>
#include <sstream>
#include <map>
#include <iomanip>
#include <math.h>
#include <numeric>
#include <stdexcept>
#include <unordered_set>
#include <unordered_map>

using namespace std;

//#pragma GCC optimize("O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("Ofast", "O3", "unroll-loops")
//#pragma GCC optimize("sse,sse2,sse3,sse4")


typedef long long ll;
typedef unsigned long long ull;
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()


const double Pi = acos(-1);

double f(double m, int n) {
    double al = Pi / n;
    double b = (Pi / 2.0) - al;
    double ang = b + m;
    double g2 = 1.0 / sin(al);
    double res1 = g2 * sin(ang);
    double ang2 = b + (al - m);
    double res2 = g2 * sin(ang2);
    return max(res1, res2);
}
signed main() {

    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int q;
    string s;
    vector<int> a, b, c;
    cin >> q;
    while (q--) {
        int n;
        cin >> n;

        n *= 2;
        double l = 0;
        double r = Pi / n;
        while (fabs(r - l) > 1e-9) {
            double m1 = l + (r - l) / 3.0;
            double m2 = r - (r - l) / 3.0;
            if (f(m1, n) > f(m2, n)) l = m1;
            else r = m2;
        }
        cout << fixed << setprecision(12) << f(l, n) << "\n";
    }
}