#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    int t;
    cin >> t;
    while (t-- > 0) {
        int r;
        cin >> r;
        cout << fixed << setprecision(16) << 1.299038105676657 * r * r << endl;
    }
}