import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        if(a!=b){
            int l = Math.max(a,b);
            int m = Math.min(a,b);
            double c = Math.sqrt(l*l-m*m);
            System.out.println(c);
        }else{
            double c = Math.sqrt(a*a*2);
            System.out.println(c);
        }
    }
}