import java.util.Scanner

object Main{
  def main(args: Array[String]): Unit = {
    val scanner = new Scanner(System.in)
    val n: Int = scanner.nextInt
    val words: List[String] = List.fill(n)(scanner.next)

    println(isEstablish(n, words.head, words.tail))
  }

  /**
    * しりとりが成立するか調べる
    * @return "Yes" or "No"
    */
  def isEstablish(n:Int, head:String, tail:List[String]) :String ={
    if (n == 1)
      "Yes"
    else
      (head.last == tail.head.head) match {
        case false => "No"
        case true => isEstablish(n-1, tail.head, tail.tail)
      }
  }
}