package main

import (
	"fmt"
	"strconv"
	"bufio"
	"os"
	"strings"
)

func main() {
	var K = nextInt()
	var primes = []int{2, 3, 5, 7, 11, 13}
	var composite = []int{4, 6, 8, 9, 10, 12}
	var count = 0.0
	for _, v1 := range (primes) {
		for _, v2 := range (composite) {
			if v1*v2 == K {
				count++
			}
		}
	}

	fmt.Println(count / 36.0)

}

var s = bufio.NewScanner(os.Stdin)

func next() string {
	s.Split(bufio.ScanWords)
	s.Scan()
	return s.Text()
}
func nextLine() string {
	s.Split(bufio.ScanLines)
	s.Scan()
	return s.Text()
}

func nextInt() int {
	i, e := strconv.Atoi(next())
	if e != nil {
		panic(e)
	}
	return i
}
func nextLong() int64 {
	i, e := strconv.ParseInt(next(), 10, 64)
	if e != nil {
		panic(e)
	}
	return i
}

func mapToInt(arr []string) []int {
	ret := make([]int, len(arr))
	for i := 0; i < len(arr); i++ {
		var err error
		ret[i], err = strconv.Atoi(arr[i])
		if err != nil {
			panic(err)
		}
	}
	return ret
}
func max(a int, b int) int {
	if a < b {
		return b
	}
	return a
}

func min(a int, b int) int {
	if a < b {
		return a
	}
	return b
}

func PrintI(args ...int) {
	fmt.Println(strings.Join(mapToString(args), " "))
}

func mapToString(arr []int) []string {
	ret := make([]string, len(arr))
	for i := 0; i < len(arr); i++ {
		ret[i] = strconv.Itoa(arr[i])
	}
	return ret
}