Problem Statement

Snuke received a positive integer $N$ from Takahashi. A positive integer $m$ is called a favorite number when the following condition is satisfied:

• The quotient and remainder of $N$ divided by $m$ are equal, that is, $\\lfloor \\frac{N}{m} \\rfloor = N \\bmod m$ holds.

Find all favorite numbers and print the sum of those.

Constraints

• All values in input are integers.
• $1 \\leq N \\leq 10^{12}$

Input

Input is given from Standard Input in the following format:

$N$

Output

Print the answer.

Sample Input 1

8

Sample Output 1

10

There are two favorite numbers: $3$ and $7$. Print the sum of these, $10$.

Sample Input 2

1000000000000

Sample Output 2

2499686339916

Watch out for overflow.