using System;

public class Program

{

    public static void Main()

    {

        int units=Convert.ToInt32(Console.ReadLine());

        if(units<=100){

            int res1= units*5;

           Console.WriteLine("cost for consumed units:" + res1); 

        }

        else if(units<=200){

            int res2=(100*5)+((units-100)*10);

           Console.WriteLine("cost for consumed units:" + res2); 

        }

        else if(units>200 ){

            int res3=(100*5)+(100*10)+((units-200)*15);

           Console.WriteLine("cost for consumed units:" + res3); 

        }

        else{

            Console.WriteLine("invalid input");

        }

        //Console.WriteLine("Hello World");

    }

}