using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
namespace Tasks
{
public class D
{
public static void Main()
{
var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
Console.SetOut(sw);
Solve();
Console.Out.Flush();
}
public static void Solve()
{
var N = Scanner.Scan<long>();
var primes = Prime.Sieve((int)1e6).ToArray();
var M = primes.Length;
var answer = 0;
var j = M - 1;
for (var i = 0; i < j; i++)
{
while (i < j)
{
var p = (long)primes[i];
var q = (long)primes[j] * primes[j] * primes[j];
try
{
checked
{
if (p * q <= N)
{
break;
}
else
{
j--;
}
}
}
catch
{
j--;
}
}
answer += j - i;
}
Console.WriteLine(answer);
}
public static class Prime
{
public static IEnumerable<long> GetFactors(long value)
{
if (value < 2) yield break;
IEnumerable<long> F(long x)
{
while (value % x == 0)
{
yield return x;
value /= x;
}
}
foreach (var v in F(2)) yield return v;
for (var i = 3L; i * i <= value; i += 2)
{
foreach (var v in F(i)) yield return v;
}
if (value > 1) yield return value;
}
public static IDictionary<long, int> GetFactorDictionary(long value)
{
var factors = new Dictionary<long, int>();
if (value < 2) return factors;
void CountUp(long n)
{
if (value % n != 0) return;
factors[n] = 0;
while (value % n == 0)
{
value /= n;
factors[n]++;
}
}
CountUp(2);
for (var i = 3L; i * i <= value; i += 2) CountUp(i);
if (value > 1) factors[value] = 1;
return factors;
}
public static IEnumerable<int> Sieve(int value)
{
if (value < 2) yield break;
yield return 2;
var sieve = new bool[(value + 1) / 2];
for (var i = 1; i < sieve.Length; i++)
{
if (sieve[i]) continue;
yield return i * 2 + 1;
for (var j = i; j < sieve.Length; j += i * 2 + 1) sieve[j] = true;
}
}
public static bool IsPrime(long value)
{
if (value == 2 || value == 3) return true;
if (value < 2 || value % 2 == 0 || value % 3 == 0) return false;
for (var i = 5L; i * i <= value; i += 6)
{
if (value % i == 0 || value % (i + 2) == 0) return false;
}
return true;
}
}
public static class Scanner
{
public static string ScanLine() => Console.ReadLine()?.Trim() ?? string.Empty;
public static string[] Scan() => ScanLine().Split(' ');
public static T Scan<T>() where T : IConvertible => Convert<T>(Scan()[0]);
public static (T1, T2) Scan<T1, T2>() where T1 : IConvertible where T2 : IConvertible
{
var line = Scan();
return (Convert<T1>(line[0]), Convert<T2>(line[1]));
}
public static (T1, T2, T3) Scan<T1, T2, T3>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible
{
var line = Scan();
return (Convert<T1>(line[0]), Convert<T2>(line[1]), Convert<T3>(line[2]));
}
public static (T1, T2, T3, T4) Scan<T1, T2, T3, T4>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible where T4 : IConvertible
{
var line = Scan();
return (Convert<T1>(line[0]), Convert<T2>(line[1]), Convert<T3>(line[2]), Convert<T4>(line[3]));
}
public static (T1, T2, T3, T4, T5) Scan<T1, T2, T3, T4, T5>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible where T4 : IConvertible where T5 : IConvertible
{
var line = Scan();
return (Convert<T1>(line[0]), Convert<T2>(line[1]), Convert<T3>(line[2]), Convert<T4>(line[3]), Convert<T5>(line[4]));
}
public static (T1, T2, T3, T4, T5, T6) Scan<T1, T2, T3, T4, T5, T6>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible where T4 : IConvertible where T5 : IConvertible where T6 : IConvertible
{
var line = Scan();
return (Convert<T1>(line[0]), Convert<T2>(line[1]), Convert<T3>(line[2]), Convert<T4>(line[3]), Convert<T5>(line[4]), Convert<T6>(line[5]));
}
public static IEnumerable<T> ScanEnumerable<T>() where T : IConvertible => Scan().Select(Convert<T>);
private static T Convert<T>(string value) where T : IConvertible => (T)System.Convert.ChangeType(value, typeof(T));
}
}
}