import java.util.*;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    List<String> saidList = new ArrayList<>();
    String ans = "Yes";
    saidList.add(sc.next());
    for (int i = 1; i < N; i++) {
      String currentWord = sc.next();
      if (saidList.contains(currentWord) || !isShiritori(currentWord, saidList.get(i-1))) {
        ans = "No";
        break;
      }
      saidList.add(currentWord);
    }
    System.out.println(ans);
  }
  private static boolean isShiritori(String curWord, String preWord) {
     return curWord.substring(0,1).equals(preWord.substring(preWord.length()-1));
  }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz