using System;

public class Program

{

    static private double hyp(double a, double b)

    {

        double c2 = b*b;

        double a2 = a*a;

        return Math.Sqrt(c2-a2);

    }

​

    public static void Main()

    {

            start:

            double input1 = double.Parse(Console.ReadLine());

            double input2 = double.Parse(Console.ReadLine());

            double output = (hyp(input1, input2));

            Console.WriteLine(output);

            goto start;

        }

    }