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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>) = shojin06e()

fun shojin06e() {
    val n = readLine()!!.toLong()

    if (n == 1L) return println(0)

    var answer = 0L

    for (i in 1..Math.sqrt(n.toDouble()).toLong()) {
        val m = (n - i) / i
        if (n / m == n % m) answer += m
    }

    println(answer)
}