using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace foryuki
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            Random r = new Random();
            int cnt = 0;
            int m = 0;
            var l = new List<int>();

            for (int i = 0; i < 30000000; i++)
            {
                cnt++;
                m += r.Next(1, 7);

                if (m > n)
                {
                    m = 0;
                }
                else if (m == n)
                {
                    l.Add(cnt);
                    m = 0;
                    cnt = 0;
                }
            }
            Console.WriteLine(l.Average());
        }

        //-------------------------------------------------------------

        static int[] ConvertStringArrayToIntArray(string[] array)
        {
            return Array.ConvertAll(array, str => int.Parse(str));
        }

        static List<int> ConvertStringArrayToIntList(string[] str)
        {
            var list = new List<int>();
            foreach (var c in str) list.Add(int.Parse(c));
            return list;
        }
    }
}