Integer Division Block

Problem Description

Given a number $n$, compute $\sum_{i=1}^n (n \bmod i)$.

The answer may be very large; output it modulo $2^{60}$.

Input Format

The first line contains one integer $n$.

Output Format

Output one number: the answer.

Sample Input

100

Sample Output

1701

Constraints

For all test cases, $1 \le n \le 10^{13}$.