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


class Magatro {
   static int a, b;
   static void Main() {
        int[] q = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
        a = q[0];
        b = q[1];
        if (a == b) {
            Console.WriteLine(Math.Sqrt(2) * (double)a);
            return;
        }
        int max = Math.Max(a, b);
        int min = Math.Min(a, b);
        Console.WriteLine(Math.Sqrt(max * max - min * min));
    }
    


}