1.
/*
 * ACM Contest training
 * Problem: 10297 - Beavergnaw
 * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=14&page=show_problem&problem=1238
 *
 * @author Patrick Bedat, Philippe Brousse, Christoph Goettschkes
 * @version 1.0, 11/14/2010
 *
 * Method : Ad-Hoc
 * Status : Accepted
 * Runtime: 0.088
 */

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;

import java.util.*;

import java.math.BigInteger;

class Main {

    static final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

    public static void main(String[] agrs) throws IOException {
        int D, V;

        do {
            String[] in = reader.readLine().split(" ");
            D = Integer.parseInt(in[0]);
            V = Integer.parseInt(in[1]);
            if(D == 0 && V == 0)
                return;

            double temp = (D*D*D*(Math.PI*2./3)-4*V)/(Math.PI*2./3);

            //dritte Wurzel
            double d = Math.pow(temp, 1./3);


            System.out.printf("%.3f%n",d);
        } while (true);
    }
}