Problem:
Score : 500 points

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.

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(void) {
	long long int n;
	long long int i;
	long long int sum = 0;
	long long int cnt = 0;
	scanf("%lld", &n);


	for (i = 1; i <= n; i++) {
		if (n % i == 0) {
			cnt = (n / i) - 1;
			if (cnt > 1){
				sum += cnt;
			}
		}
	}

	printf("%lld\n", sum);
	

	return 0;
}