#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;
using ll = long long;

#include<iomanip>
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int t;
    cin>>t;
    while(t--){
        long double ans = 1.299038105676657;
        int r;
        cin>>r;
        ans *= r * r;
        cout<<setprecision(30)<<fixed<<ans<<endl;
    }
}