import scala.annotation.tailrec
import scala.io.StdIn.*



def primeFactors(value: Int): List[Int] =
  def inner(v: Int, p: Int): List[Int] =
    v match
      case 1 => Nil
      case _ if p * p > v => v::Nil
      case _ if v % p == 0 => p::inner(v / p, p)
      case _ => inner(v, p + 1)
  inner(value, 2)

@main def main =
  val n = readLine().toInt
  val factor = primeFactors(n)
  println(factor.sum)