import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		sc.close();
		String tmp = "142857";
		if (N == 0) System.out.print(0);
		else {
			System.out.print("0.");
			for (int i = 0; i < N / 6; ++i) System.out.print(tmp);
			for (int i = 0; i < N % 6; ++i) System.out.print(tmp.charAt(i));
		}
	}
}