import scala.collection.mutable
import scala.io.StdIn.readLine

object Main {
  def main(args:Array[String]) = {
    val n = readLine().toInt
    val a = readLine().split(" ").map(_.toInt).sorted
    val m = mutable.Map.empty[Int,Int]
    a.foreach((k) =>  m += k -> (1 + m.getOrElse(k,0)))
    val ans = a.count((k) => m(k) == 1)
    println(ans)
  }
}