import java.util.Scanner;

public class techModuleMToKm {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double meters = Double.parseDouble(scanner.nextLine());
        double convert = meters / 1000;
        double round = Math.nextUp(convert);

        System.out.printf("%.2f ", round);
    }
}