package yukicoder;

import java.util.Scanner;

public class No_419 {
public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int a = sc.nextInt();
	int b = sc.nextInt();
	sc.close();
	if(a == b){
		double c = a * Math.sqrt(2);
		System.out.println(c);
	}else{
	double abs = Math.abs(Math.pow(a, 2) - Math.pow(b, 2));
	double c = Math.sqrt(abs);
	System.out.println(c);
	}
}
}