import java.util.*;
 
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.next());
        ArrayList<String> list = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            String tmp = sc.next();
            if (list.contains(tmp)) {
                System.out.println("No");
                return;
            } else {
                list.add(tmp);
            }
        }
        for (int i = 1; i < n; i ++) {
            char end = list.get(i - 1).charAt(list.get(i - 1).length() - 1);
            if (list.get(i).charAt(0) != end) {
                System.out.println("No");
                return;
            }
        }
        System.out.println("Yes");
    }
}
/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