package com.project.znanija.vikaaaaaso.question;

import java.util.Scanner;

public class Main {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int x = in.nextInt();

int y = in.nextInt();

double c = 5*x+6*y/(5*x-2*y);

System.out.print(c);

}

}