using System;
using System.Collections.Generic;

namespace PerfectSquareFractions
{
    class Program
    {
        static int PerfArc(int n)
        {
            int root = (int)Math.Sqrt(n);
            if (root * root == n)
            {
                return 0;
            }
            int a = 1;
            List<int> listaint = new List<int> { root };
            int den = n - root * root;
            List<double> lista_inv_frac = new List<double> { (Math.Sqrt(n) + root) / den };
            int per = 0;
            while (true)
            {
                int part_int = (int)lista_inv_frac[lista_inv_frac.Count - 1];
                root = (den * part_int) / a - root;
                a = den / a;
                den = n - root * root;
                double invfrac = a * (Math.Sqrt(n) + root) / den;
                listaint.Add(part_int);
                lista_inv_frac.Add(invfrac);
                per++;
                if (invfrac == lista_inv_frac[0])
                {
                    return per;
                }
            }
        }

        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int cntodd = 0;
            for (int k = 2; k <= n; k++)
            {
                if (PerfArc(k) % 2 == 1)
                {
                    cntodd++;
                }
            }

            Console.WriteLine(cntodd);
        }
    }
}