/* -*- coding: utf-8 -*-
 *
 * 3691.cc:  No.3691 Calculate Mu Sum - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 10000000;

/* typedef */

/* global variables */

bool primes[MAX_N + 1];
int pds[MAX_N + 1], myus[MAX_N + 1];

/* subroutines */

void gen_primes(int maxp) {
  fill(primes, primes + maxp + 1, true);
  primes[0] = primes[1] = false;
  fill(pds, pds + maxp + 1, 0);
  pds[1] = 1;

  int p;
  for (p = 2; p * p <= maxp; p++)
    if (primes[p]) {
      pds[p] = p;
      for (int q = p * p; q <= maxp; q += p) {
	primes[q] = false;
	if (! pds[q]) pds[q] = p;
      }
    }
  for (; p <= maxp; p++)
    if (primes[p]) pds[p] = p;
}

/* main */

int main() {
  gen_primes(MAX_N);

  int n;
  scanf("%d", &n);

  myus[1] = 1;
  int sum = 1;
  for (int i = 2; i <= n; i++) {
    int j = i / pds[i];
    if (j % pds[i] == 0) myus[i] = 0;
    else myus[i] = -myus[j];
    sum += myus[i];
    //printf(" myus[%d] = %d\n", i, myus[i]);
  }

  printf("%d\n", sum);
  
  return 0;
}