import java.util.Scanner;
public class DeziHexa {

    public static void main(String[] args) {

        char hexadezimalzeichen[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
        String hexadezimale = "";

        Scanner scanner = new Scanner (System.in);

        int dezimale = scanner.nextInt();
        if(dezimale >= 0) {

            while(dezimale > 0) {
                int rest = dezimale % 16;
                hexadezimale = hexadezimalzeichen[rest] + hexadezimale;

                dezimale /= 16;

            }
            System.out.println(hexadezimale);
        }else
            System.out.println("ungültige Eingabe");

    }

}