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>
#include <math.h>

int main()
{
    long long int n, m, ans=0;
    scanf("%d", &n);
    for(int i=1;i<sqrt(n);i++){
        if(n % i == 0){
            m = n / i;
            if(m > 2 && (m-1)!= i && m > i) {
                ans+= m-1;
                printf("i=%d, %d\n", i, m-1);
            }
        } 
    }
    printf("%llu\n", ans);
    return 0;
}