import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);
        int price = console.nextInt();
        int cost = 0;

        //write your code here......
        cost = (int) ((price>=5000)?0.6*price:(price>=2000)?0.7*price:(price>=500)?0.8*price:(price>=100)?0.9*price:price);
        

        System.out.println(cost);
    }
}