Problems
A*B*C
A*B*C
Given a positive integer $k$, find the number of triples of positive integers $(a, b, c)$ such that $a \cdot b \cdot c \le k$. Two triples that only differ in the order of numbers are also distinguished.
\InputFile
One integer $k~(1 \le k \le 2 \cdot 10^5)$.
\OutputFile
Print the number of triples of positive integers $(a, b, c)$ such that $a \cdot b \cdot c \le k$.
Input example #1
2
Output example #1
4
Input example #2
10
Output example #2
53