import java.util.Scanner

object Main {
  def main(args: Array[String]): Unit = {

    val sc = new Scanner(System.in)
    val k = sc.nextInt()
    val s = sc.next()

    if (s.length > k) {
      println(s.substring(0, k) + "...")
    } else {
      println(s)
    }

  }

}
