NK ran out of novel problem ideas, so he is going back to the basics.

Given a integer \(N\), count the number of unordered integer triples \((a, b, c)\) such that \(a \cdot b \cdot c \le N\).

Constraints

\(1 \le N \le 10^{10}\)

Input Specification

The first line will contain one integer \(N\).

Output Specification

Output the number of triples satisfying the equation.

Sample Input 1

6

Sample Output 1

8

Explanation

The triples are: \((1, 1, 1)\), \((1, 1, 2)\), \((1, 1, 3)\), \((1, 1, 4)\), \((1, 1, 5)\), \((1, 1, 6)\), \((1, 2, 2)\), \((1, 2, 3)\),

Sample Input 2

100820

Sample Output 2

1347914