#!/usr/bin/env pypy3

from pprint import pprint
from string import ascii_lowercase as letter
from sys import setrecursionlimit, stdin
from typing import Dict, Iterable, Set


INF: int = (1 << 62) - 1
MOD1000000007 = 10**9 + 7
MOD998244353 = 998244353
readline = stdin.readline
input = lambda: stdin.readline().rstrip('\r\n')


def inputs(type_=int):
    ins = input().split()

    if isinstance(type_, Iterable):
        return [t(x) for t, x in zip(type_, ins)]
    else:
        return list(map(type_, ins))


def input_(type_=int):
    a, = inputs(type_)
    return a


def input1() -> int:
    return int(readline())


inputi = input1


def input2():
    a = readline().split()
    assert len(a) == 2
    a[0] = int(a[0])
    a[1] = int(a[1])
    return a


def input3():
    a = readline().split()
    assert len(a) == 3
    a[0] = int(a[0])
    a[1] = int(a[1])
    a[2] = int(a[2])
    return a


def input4():
    a = readline().split()
    assert len(a) == 4
    a[0] = int(a[0])
    a[1] = int(a[1])
    a[2] = int(a[2])
    a[3] = int(a[3])
    return a


yn = ['no', 'yes']
Yn = ['No', 'Yes']
YN = ['NO', 'YES']


# start coding
def isqrt(n):
    """
    nの平方根をニュートン法で求める.

    計算量: O(log(n))以下 (O(loglog(n))?)
    Ref: http://www.ritsumei.ac.jp/se/~osaka/rejime/suuti/suuti2001.pdf
    """
    x, y = n, (n + 1) // 2
    while y < x:
        x, y = y, (y + n // y) // 2
    return x


def factor(n: int) -> Dict[int, int]:
    if n < 2:
        return dict()

    res = dict()
    for i in range(2, isqrt(n) + 1):
        if n % i == 0:
            res[i] = 0
            while n % i == 0:
                res[i] += 1
                n //= i
    if n != 1:
        res[n] = 1

    return res


class Osak:

    def __init__(self, max_n: int) -> None:
        self.max_n = max_n
        self._create_table()

    def _create_table(self):
        """
        (max_n + 1)個の要素を持つリストaであってa[k]がkの最小の素因数であるようなリストをself.tableに設定する.
        計算量: O(max_n * loglog(max_n))
        """
        a = [None] * (self.max_n + 1)
        for k in range(2, self.max_n + 1):
            if a[k] is not None:
                continue

            for p in range(k, self.max_n + 1, k):
                if a[p] is None:
                    a[p] = k

        self.table = a

    def is_prime(self, n: int) -> bool:
        return n >= 2 and self.table[n] == n

    def factor(self, n: int) -> dict:
        assert 0 <= n < len(self.table)
        if n <= 1:
            return {}

        d = {}
        while n != 1:
            k = self.table[n]
            d[k] = 0
            while n % k == 0:
                d[k] += 1
                n //= k

        return d

    def __str__(self) -> str:
        return f'{self.__class__.__name__} <max_n: {self.max_n}>'


n = inputi()
osak = Osak(n)
res = 0
for i in range(1, n + 1):
    d = factor(i)
    t = 1
    for p, c in d.items():
        if c % 2 == 1:
            t *= p

    res += isqrt(n // t)

print(res)