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: Runtime Error)

#include<stdio.h>
int main(){
  int a=0,n,b=0,i;
  scanf("%d",&n);
  int s[n];
  for(i=0;i<n;i++)
    s[i] = 0;

  for(i=1;i<=n;i++){
    if((n/i) == (n%i)){
      s[b] = i-1;
      b++;
    }
  }

  for(i=0;i<b;i++)
    a += s[i];

  printf("%d",a);

  return 0;
}