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;
bool isprime(long long x) {
  if (x == 2) return true;
  if (x < 2 || x % 2 == 0) return false;
  for (long long i = 3; i * i <= x; i += 2) {
    if (x % i == 0) return false;
  }
  return true;
}
int main() {
  long long n;
  cin >> n;
  long long i;
  int j = 0, q = 0;
  int a[n + 5];
  int b[n + 5];
  int c[n + 5];
  for (i = 2; i <= n; i++) {
    if (isprime(i)) {
      a[j] = i;
      j++;
    } else {
      b[q] = i;
      q++;
    }
  }
  int k = 0;
  long long l;
  long long y = 0;
  for (i = 0; i < q; i++) {
    int o = 0;
    for (l = 0; l < j; l++) {
      if (b[i] % a[l] == 0) o++;
    }
    c[y] = o;
    y++;
  }
  for (i = 0; i < y; i++)
    if (c[i] == 2) k++;
  cout << k << endl;
  return 0;
}
