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 Python (3.8.2) (judge verdict: Wrong Answer)

n=int(input())

# total=0
# i=1
# while i*i<=n:
#     if n%i==0:
#         total+=(n//i)-1
    
#     i+=1

def make_divisors(n):
    lower_divisors , upper_divisors = [], []
    i = 1
    while i*i <= n:
        if n % i == 0:
            lower_divisors.append(i)
            if i != n // i:
                upper_divisors.append(n//i)
        i += 1
    return lower_divisors + upper_divisors[::-1]

arr = make_divisors(n)
d={}
for i in arr:
    d[i]=0
total=0

for j in range(len(arr)):
    t = arr[j]

    if t**2 == n:
        d[t]=1
        continue
    if d[t]==0:
        total+=(n//t)-1
        d[t]=1
        d[n//t]=1

print(total)