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

namespace yuki_419
{
    class Program
    {
        static void Main(string[] args)
        {
            var t = scan;
            var c = t.Max();
            var b = t.Min();

            double a = Math.Sqrt(c * c - b * b);

            if(c !=b) Console.WriteLine(a.ToString("0.0000000"));
            else
            {
                a = c * Math.Sqrt(2);
                Console.WriteLine(a.ToString("0.0000000"));
            }
            
        }

        static int[] scan { get { return Array.ConvertAll(Console.ReadLine().Split(), int.Parse); } }
    }
}