object Main extends App{
  var n = scala.io.StdIn.readInt
  var s = scala.io.StdIn.readLine
  var length = s.length
  if (length-n <= 0){
    printf("%s",s)
  }else{
    for(i <- 1 to n){
      printf("%s",s.apply(0))
      s=s.drop(1)
    }
    for(l <- 1 to length-n){
      printf(".")
    }
  }
}
