import java.util.ArrayList;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		ArrayList<String> arr = new ArrayList<>();
		String start = null;
		String end = null;
		String judge = "Yes";
		
		for(int i = 0; i < n ; i++) {
			String w = scan.next();
			if (arr.contains(w)) {
				judge = "No";
				break;
			}
			
			start = w.substring(0, 1);
			if(end != null && !start.equals(end)) {
				judge = "No";
				break;
			}
			arr.add(w);
			end = w.substring(w.length()-1);
		}
		System.out.println(judge);
		scan.close();
	}
}
/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