#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int t[3000], pr[3000], np = 0;
  for (int i = 0; i < n; i++) {
    t[i] = 0;
  }
  for (int i = 1; i < n; i++) {
    if (t[i] == 0) {
      pr[np] = i + 1;
      np++;
      int j = 2;
      while (j * (i + 1) <= n) {
        t[j * (i + 1) - 1] = 1;
        j++;
      }
    }
  }
  int alm = 0, p = 1;
  for (int i = 0; i < np; i++) {
    for (int j = i + 1; j < np; j++) {
      int p = pr[i], q = pr[j];
      while (p <= n) {
        q = p * pr[j];
        while (q <= n) {
          q = q * pr[j];
          alm++;
        }
        p = p * pr[i];
      }
    }
  }
  cout << alm << endl;
}
