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 Go (1.6) (judge verdict: Wrong Answer)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func allAtoi(num []string) []int {
	conv := make([]int, len(num))
	for i, item := range num {
		conv[i], _ = strconv.Atoi(item)
	}
	return conv
}

func main() {
	n, _ := strconv.Atoi(nextLine())
	ans := 0
	sho := 0
	amari := 0
	for j := 3; j <= n/2; j++ {
		sho = n / j
		amari = n % j
		if sho == amari {
			ans += j
		}
	}
	ans += n - 1
	fmt.Println(ans)
}