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++14 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)



#include <bits/stdc++.h>
#include <vector>
#include <math.h>

using namespace std;


int main(){

 long long  n,sum=0;
 cin>>n;

  for(int i=1;i<=n;i++){

    int quo = n/i;
    int rem = n%i;

    if(quo == rem)
        sum += i;
  }

  cout<<sum<<endl;

return 0;
 }