//     Author: Rodney Shaghoulian
//     Github: github.com/RodneyShag
// HackerRank: hackerrank.com/RodneyShag

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.lang.reflect.*;
import java.security.Permission;

// This is not a well-designed question. I recommend skipping this problem. 
// The provided code requires a very specific and unconventional interface that 
// the Calculate class needs to follow. A working solution is provided below.

class Calculate {
    static Scanner scan = new Scanner(System.in);
    static Calculate output = new Calculate();

    public static Calculate do_calc() {
        return output;
    }
    
    public int get_int_val() throws IOException, NumberFormatException {
        int x = scan.nextInt();
        if (x <= 0) {
            throw new NumberFormatException("All the values must be positive");
        }
        return x;
    }
    
    public double get_double_val() throws IOException, NumberFormatException  {
        double x = scan.nextDouble();
        if (x <= 0) {
            throw new NumberFormatException("All the values must be positive");
        }
        return x;
    }
    
    public double get_volume(int a) { // cube
        return a * a * a;
    }
    
    public double get_volume(int l, int b , int h) { // cuboid
        return l * b * h;
    }
    
    public double get_volume(double r) { // hemisphere
        return (2 * Math.PI * r * r * r) / 3;
    }
    
    public double get_volume(double r, double h) { // cylinder
        return  Math.PI * (r * r) * h;
    }
    
    void display(double value) {
        System.out.format("%.3f%n", value);
    }
}

public class Solution {
    public static void main(String[] args) {
        DoNotTerminate.forbidExit();
        try {
            Calculate cal = new Calculate();
            int T = cal.get_int_val();
            while (T--> 0) {
                double volume = 0.0;
                int ch = cal.get_int_val();
                if (ch == 1) {
                    int a = cal.get_int_val();
                    volume = Calculate.do_calc().get_volume(a);
                } else if (ch == 2) {
                    int l = cal.get_int_val();
                    int b = cal.get_int_val();
                    int h = cal.get_int_val();
                    volume = Calculate.do_calc().get_volume(l, b, h);
                } else if (ch == 3) {
                    double r = cal.get_double_val();
                    volume = Calculate.do_calc().get_volume(r);
                } else if (ch == 4) {
                    double r = cal.get_double_val();
                    double h = cal.get_double_val();
                    volume = Calculate.do_calc().get_volume(r, h);
                }
                cal.output.display(volume);
            }
        } catch (NumberFormatException e) {
            System.out.print(e);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (DoNotTerminate.ExitTrappedException e) {
            System.out.println("Unsuccessful Termination!!");
        }
    } // end of main
} //end of Solution

/**
*This class prevents the user form using System.exit(0)
* from terminating the program abnormally.
*
*/
class DoNotTerminate {
    public static class ExitTrappedException extends SecurityException {}
    public static void forbidExit() {
        final SecurityManager securityManager = new SecurityManager() {
            @Override
            public void checkPermission(Permission permission) {
                if (permission.getName().contains("exitVM")) {
                 throw new ExitTrappedException();
                }
            }
        };
        System.setSecurityManager(securityManager);
    }
} //end of Do_Not_Terminate