import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long a = scan.nextLong();
		long b = scan.nextLong();
		scan.close();
		if(a == b) {
			double ans = Math.sqrt(a * a + b * b);
			System.out.println(ans);
		}else {
			long min = Math.min(a, b);
			long max = Math.max(a, b);
			double ans = Math.sqrt(max * max - min * min);
			System.out.println(ans);
		}

	}
}