object Main extends App {
  import scala.io.StdIn._

  val n = readInt
  val (even, odd) = readLine.trim.split(' ').map(_.toInt).partition(_ % 2 == 0)
  println(
    if (odd.length % 2 == 1) (even.sum + odd.sum - odd.min) / 2
    else (even.sum + odd.sum) / 2
  )
  implicit class Scope[T](val value: T) extends AnyVal {
    @inline
    def let[A](func: T ⇒ A): A = func(value)
  }
}

