object Main {

  def main(args: Array[String]): Unit = {
    scala.io.StdIn.readLine()
    val str = scala.io.StdIn.readLine()
    val k = scala.io.StdIn.readLine().toInt
    val target = str(k)
    println(str.map {
      case c @ `target` => c
      case _ => '*'
    })
  }

}