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 long long mod = 1e9 + 7;
long long noOfSetBits(long long x) { return __builtin_popcountll(x); }
long long countBits(long long x) { return (long long)log2(x) + 1; }
vector<int> v;
void helper() {
  int n = 3007;
  v.resize(n);
  for (int i = 1; i < n; i++) v[i] = i;
  for (int i = 2; i * i < n; i++) {
    if (v[i] != i) continue;
    for (int j = i * i; j < n; j += i) {
      if (v[j] == j) v[j] = i;
    }
  }
}
int check(int x) {
  int cnt = 0;
  while (x > 1) {
    int t = 0, y = v[x];
    while (x % y == 0 and x > 1) {
      x = x / y;
      t = 1;
    }
    cnt += t;
  }
  return (cnt == 2);
}
int main(int argc, char const *argv[]) {
  ios_base::sync_with_stdio(false);
  long long test = 1, k, x, y, pos, n, i, p, q, r, m, c, a, b;
  helper();
  while (test--) {
    cin >> n;
    long long cnt = 0;
    for (int i = 2; i <= n; i++) {
      if (check(i)) cnt++;
    }
    cout << cnt;
    cout << "\n";
  }
  return 0;
}
