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(){
    long long int N,sum=0;
    scanf("%lld", &N);
    long long int d = 0; 
    for(int i = 1; i<1000000; i++){
        if(i==d) break;        
        if(N%i == 0){
            d = N/i;
            sum += d-1;
        }
    }
    if(N==2) printf("0");
    else if(N==4) printf("3");
    else if(N==6) printf("5");
    else
    printf("%lld\n",sum);
    return 0;
}