Problem: If an integer a is divisible by another integer b, then b is called the divisor of a.

For example: 12 has positive 6 divisors. They are 1, 2, 3, 4, 6 and 12.

Let’s define a function D(n) — number of integers between 1 and n (inclusive) which has exactly four positive divisors.

Between 1 and 10 only the integers 6, 8 and 10 has exactly four positive divisors. So, D(10) = 3.

You are given an integer n. You have to calculate D(n).

Input

The only line contains integer n (1 ≤ n ≤ 1011) — the parameter from the problem statement.

Output

Print the only integer c — the number of integers between 1 and n with exactly four divisors.

Examples

Input

10


Output

3


Input

20


Output

5

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
long long n, m, k, sum, f[320001], g[320001];
int main() {
  cin >> n, k = pow(n + 1, 1.0 / 3);
  for (m = 1; m * m <= n; m++) g[m] = m, f[m] = n / m;
  m--;
  for (long long i = 2; i <= m; i++)
    if (g[i] > g[i - 1]) {
      for (long long j = 1; j <= min(m, n / i / i); j++) {
        f[j] += g[i - 1];
        if (i * j <= m)
          f[j] -= f[i * j];
        else
          f[j] -= g[n / i / j];
      }
      for (long long j = m; j >= i * i; j--) g[j] -= g[j / i] - g[i - 1];
    }
  sum = g[k] - 1;
  for (long long i = 2; i <= m; i++)
    if (g[i] > g[i - 1]) sum += f[i] - g[i];
  cout << sum << "\n";
}