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

namespace yukicoder
{
    public class Program
    {
        public static void Main()
        {
            var a = Console.ReadLine().Split(' ').Select(x => Math.Pow(double.Parse(x), 2)).ToArray();
            if (a[0] == a[1])
            {
                Console.WriteLine(Math.Sqrt(a.Sum()));
            }
            else
            {
                Console.WriteLine(Math.Sqrt(Math.Abs(a[0]-a[1])));
            }
        }
    }
}