import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		int a = scn.nextInt();
		int b = scn.nextInt();
		
		if(a<b){
			int sub = a;
			a = b;
			b = sub; 
		}
		double ans = Math.sqrt(a*a-b*b);
		
		System.out.println(ans);

	}
}