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.

Examples

Input

8

Output

10

Input

1000000000000

Output

2499686339916

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