import java.util.Scanner;

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

	}
}