import scala.io.StdIn.{readInt, readLine}

case class Shiritori(words: List[String]) {

  require(words.toSet.size == words.size)

  @scala.annotation.tailrec
  private def recursive(before: Char, residue: List[String]): Boolean =
    residue match {
      case Nil => true
      case h :: t if before == h.head => recursive(h.last, t)
      case _ => false
    }

  def isSatisfy: Boolean =
    recursive(words.head.last, words.tail)

}

object Main extends App {

  val n = readInt
  val words = (1 to n) map ( _ => readLine.trim) toList

  if (Shiritori(words).isSatisfy) println("Yes") else println("No")

}