A × B × C

Points 100 2.0s 256M

This task is adapted from ARC113 A - A*B*C.

You are given a positive integer \(K\). Count the number of ordered triples \((A, B, C)\) satisfying \(A \times B \times C \le K\). Since the triples are ordered, for example \((1, 1, 2)\) and \((1, 2, 1)\) are considered distinct.

Input

The input consists of a single line containing the integer \(K\).

Constraints

  • \(1 \le K \le 10^{12}\)

Output

Output a single integer equal to the desired count.

Scoring

There are three subtasks. Each subtask contains multiple test cases, and you earn the subtask's score only if you solve all of its tests.

  • Subtask \(1\) (20 points): \(K \le 500\).
  • Subtask \(2\) (40 points): \(K \le 10^7\).
  • Subtask \(3\) (40 points): no additional constraints.

Sample Input 1

2

Sample Output 1

4

Sample Input 2

10

Sample Output 2

53

Sample Input 3

10000000

Sample Output 3

1421760251

Sample Input 4

1000000000000

Sample Output 4

402439152166882

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