using System;

public class Program

{

    public static void Main()

    {

        string p = Console.ReadLine();

            int price ;

            bool check = int.TryParse(p, out price);

            if (price<=0)

            {

                Console.WriteLine("輸入錯誤");

            }else if (price <= 100 )

                {

                    Console.WriteLine(price);

                }

                else if (price <= 200 && price > 100)

                {

                    Console.WriteLine((float)price * 0.9);

                }

                else if (price <= 300 && price > 400)

                {

                    Console.WriteLine((float)price * 0.8);

                }

                else 

                {

                    Console.WriteLine((float)price * 0.7);

                }

    }

}