using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Linq;

class Magatro
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        if (N % 2 == 1) Console.WriteLine(N);
        else Console.WriteLine(N / 2);
    }

}