import java.io.{BufferedReader, InputStreamReader}

import scala.collection.mutable.ArrayBuffer

object Main {
  def main(args: Array[String]): Unit = {
    val in = new BufferedReader(new InputStreamReader(System.in))

    val Array(n, m) = in.readLine.split("\\s+").map(_.toInt)
    var prices = ArrayBuffer(in.readLine.split("\\s+").map(_.toLong) : _*)

    (1 to m).foreach { _ =>
      prices = prices.sortWith((a,b) => a > b)
      prices(0) /= 2
    }

    System.out.println(prices.sum)
  }
}
