import java.util.*;
import static java.lang.System.*;

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