A number is called almost prime if it has exactly two distinct prime divisors. For example, numbers 6, 18, 24 are almost prime, while 4, 8, 9, 42 are not. Find the amount of almost prime numbers which are between 1 and n, inclusive.

Input

Input contains one integer number n (1 ≤ n ≤ 3000).

Output

Output the amount of almost prime numbers between 1 and n, inclusive.

Examples

Input

10


Output

2


Input

21


Output

8
#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1);
const double eps = 1e-9;
const int inf = 2000000000;
const long long infLL = 9000000000000000000;
int dx[] = {0, 0, +1, -1};
int dy[] = {+1, -1, 0, 0};
bool check_prime(int t) {
  for (int i = 2; i * i <= t; i++) {
    if (t % i == 0) return false;
  }
  return true;
}
int main() {
  long long n;
  cin >> n;
  ;
  vector<int> v;
  v.push_back(2);
  for (int i = 3; i <= n; i += 2) {
    if (check_prime(i)) {
      v.push_back(i);
    }
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    int cnt = 0;
    for (int j = 0; j < v.size(); j++) {
      if (i % v[j] == 0) cnt++;
    }
    if (cnt == 2) ans++;
  }
  cout << ans << '\n';
}
