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()
    {
        long D = long.Parse(Console.ReadLine());
        Console.WriteLine((double)D * 1.08);
    }
  
}