using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;



class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        double[] inpt = Reader.ReadLine().Split(' ').Select(a=>double.Parse(a)).ToArray();

        double ans = 1;
        if(inpt[0] == inpt[1]) {
            ans = Math.Sqrt(Math.Pow(inpt[0], 2) * 2);
        } else {
            double yoko = inpt.Min();
            double naname = inpt.Max();
            ans = Math.Sqrt(Math.Pow(naname, 2) - Math.Pow(yoko, 2));
        }


        Console.WriteLine(ans.ToString("#0.##############"));
        


    }

    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"

1 1





";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}