import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    Map<String,String> m = new HashMap<String,String>();
    String preString = sc.next();
    char lastChar = preString.charAt(preString.length() - 1);
    m.put(preString,preString);

    for(int i=1;i<N;i++){
      String string = sc.next();
      if(string.charAt(0) != lastChar || m.containsKey(string)){
        System.out.println("No");
        return;
      }
      lastChar = string.charAt(string.length() - 1);
      m.put(string,string);
    }
    System.out.println("Yes");
    return;
  }
}

/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