import java.io.*;
import java.util.*;


public class Main_yukicoder419 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		int a = sc.nextInt();
		int b = sc.nextInt();

		double c;
		if (a == b) {
			c = Math.sqrt(a * a + b * b);
		} else {
			c = Math.sqrt(Math.abs(a * a - b * b));
		}

		pr.printf("%.7f\n", c);
	}

	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);

		solve();

		pr.close();
		sc.close();
	}

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}