
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		
		String[] w = new String[n];
		Set<String> set = new HashSet<>();
		for (int i = 0; i < n; i++) {
			w[i] = sc.next();
			set.add(w[i]);
		}
		
		for (int i = 1; i < n; i++) {
			if (w[i].charAt(0) != w[i - 1].charAt(w[i - 1].length() - 1)) {
				System.out.println("No");
				return;
			}
		}
		
		System.out.println((set.size() == n) ? "Yes" : "No");

	}

}

/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