public class Program
{
    public static void Main()
    {
        long num = long.Parse(Console.ReadLine() ?? string.Empty);
        //string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string str = Console.ReadLine() ?? string.Empty;


        double ss = (num * 0.08) + num;

        Console.WriteLine(ss);

    }
}