import java.util.Scanner

import scala.collection.mutable

object Main extends App {
  val sc = new Scanner(System.in)
  val n = sc.nextInt
  val as = Vector.fill(n / 2)((sc.nextInt, sc.nextInt))

  val odd = mutable.Map[Int, Int]()
  val even = mutable.Map[Int, Int]()

  as.foreach { case (o, e) =>
    odd.put(o, odd.getOrElse(o, n / 2) - 1)
    even.put(e, even.getOrElse(e, n / 2) - 1)
  }

  val oo = odd.toSeq.sortBy(a => a._2)
  val ee = even.toSeq.sortBy(a => a._2)

  val res = (oo, ee) match {
    case _ if oo.head._1 != ee.head._1 => oo.head._2 + ee.head._2
    case (o1 +: o2 +: _, e1 +: e2 +: _) => (o1._2 + e2._2) min (o2._2 + e1._2)
    case (o1 +: _, _ +: e2 +: _) => o1._2 + e2._2
    case (_ +: o2 +: _, e1 +: _) => e1._2 + o2._2
    case _ => n / 2
  }

  println(res)
}
