using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var ans = 0;
        for (var i = 0; i <= 20; ++i)
        {
            for (var j = 0; j <= i; ++j)
            {
                if (i * 5 + j * 2 > n) break;
                if ((n - i * 5 - j * 2) % 3 == 0) ++ans;
            }
        }
        WriteLine(ans);
    }
}