package yukicoder;

import java.util.Scanner;

public class N419
{

	public static void main(String[] args)
	{
		Scanner sc=new Scanner (System.in);
		int a=sc.nextInt(),b=sc.nextInt();
		double c=Math.sqrt(Math.abs(a*a-b*b));
		System.out.printf("%.7f\n",c);
	}

}