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

public class Yuki419
{
	public static void Main()
	{
		var ab = Console.ReadLine().Split().Select(x => double.Parse(x)).ToArray();
		
		if(ab[0] == ab[1]) Console.WriteLine(Math.Sqrt(ab[0] * ab[0] + ab[1] * ab[1]));
		else Console.WriteLine(Math.Sqrt(Math.Abs(ab[0] * ab[0] - ab[1] * ab[1])));
	}
}