using System.Linq;
using System;

public class Hello
{
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var a = int.Parse(line[0]);
        var b = int.Parse(line[1]);
        Console.WriteLine(getAns(a,b));
    }
    public static double getAns (int a, int b)
    {
        var ans = new double[2];
        ans[0] = ans[1] = 1000000;
        if (b > a)  return  getAns(b, a);
        var w = Math.Sqrt(a * a + b * b);
        if (check(a, b, w)) ans[0] = w;
        var w2 = Math.Sqrt(a * a - b * b);
        if (check(a, b, w2)) ans[1] = w2;
        return ans.Min();
    }
    public static bool check (int a, int b, double c)
    {
        var a2 = (double)a;
        var b2 = (double)b;
        if (a2 + b2 <= c) return false;
        if (a2 + c <= b2) return false;
        if (b2 + c <= a2) return false;
        return true;
    }
}