import java.util.Scanner;


public class Y419 {
	Y419() {
	    Scanner sc = new Scanner(System.in);
	    double a = sc.nextDouble();
	    double b= sc.nextDouble();
	    
	    if (a > b) {
	    	double tmp = a;
	    	a = b;
	    	b = tmp;
	    }
	    
	    double c = Math.sqrt(b*b - a*a);
	    
	    System.out.println(c);
	}
	public static void main(String argv[]) {
		new Y419();
	}
}