public class Converter {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double milesPerGallon = Double.parseDouble(scanner.nextLine());
        if (milesPerGallon>0&&milesPerGallon<=100){
            double kilometerForlitter = milesPerGallon*(1.6/4.54);
            double consumptionLittersForHundret= 100/kilometerForlitter;
            System.out.print(""+Math.floor(consumptionLittersForHundret)+" litters per 100 km");


        }

    }
}