using System.Numerics;

public class Program
{
    public static void Main()
    {

        //BigInteger num = BigInteger.Parse(Console.ReadLine() ?? string.Empty);
        int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string str = Console.ReadLine() ?? string.Empty;

        int count = 0;
        if (num == 0 || num ==1)
        {
            Console.WriteLine(num)
                ; return;
        }
        if (num % 2 == 0)
        {
            count += num / 2;
            Console.WriteLine(count);
        }
        else
        {
            count += num / 2;
            count += num % 2;
            Console.WriteLine(count);
        }

    }

}