import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scan = new Scanner(System.in); int K = scan.nextInt(); scan.close(); int []a = {2, 3, 5, 7, 11, 13}; int []b = {4, 6, 8, 9, 10, 12}; int cnt = 0; for(int i = 0; i < 6; i++) { for(int j = 0; j < 6; j++) { if(K == a[i] * b[j]) { cnt ++; } } } float ans = (float) cnt / 36; System.out.println(ans); } }