using System;
using System.Collections.Generic;
class Program
{
	static void Main(string[] args)
	{
		string[]str = Console.ReadLine().Split();
		double A = double.Parse(str[0]);
		double B = double.Parse(str[1]);
		double ans = Math.Sqrt(B * B - A * A);
		Console.WriteLine(ans);
	}
}