import java.util.*;

public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);
    int N = Integer.parseInt(sc.nextLine());
    Set<String> set = new HashSet<>();
    String S = sc.nextLine();
    set.add(S);
    
    String ans = "Yes";
    char c = S.charAt(S.length()-1);
    for(int i = 1; i < N; i++){
      String s = sc.nextLine();
      int n = set.size();
      set.add(s);
      if(c != s.charAt(0) || n == set.size()){
        ans = "No";
      }
      c = s.charAt(s.length()-1);
    }
    System.out.println(ans);
  }
}
/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