package com.javarush.task.task04.task0412;

/*
Положительное и отрицательное число
*/

import java.io.*;

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            Integer.parseInt(reader.readLine());
                int number = reader.read();
                    if (number > 0){
                        System.out.println(number * 2);
                    }
                    else if (number < 0){
                        System.out.println(number + 1);
                    }
                    else
                        System.out.println(0);