import java.util.Scanner;

public class No153 {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		Short n = sc.nextShort(), c = 0;
		byte[] s = { 2, 3, 5, 7, 11, 13 }, g = { 4, 6, 8, 9, 10, 12 };
		for (byte i = 0; i < 36; i++)
			if (n == s[i % 6] * g[i / 6])c++;
		System.out.println(c/36d);
	}
}