
import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();

		String[] list = new String[n];
		for (int i = 0; i < list.length; i++) {
			list[i] = scan.next();
		}

		char previous = list[0].charAt(list[0].length() - 1);

		String ans = "Yes";

		Set<String> linkedHashSet = new LinkedHashSet<String>();
		for (int i = 0; i < list.length; i++) {
			linkedHashSet.add(list[i]);
		}
		
		if(linkedHashSet.size() != list.length) {
			ans = "No";
		} else {
			for (int i = 1; i < list.length; i++) {
				if (previous != list[i].charAt(0)) {
					ans = "No";
					break;
				}
				previous = list[i].charAt(list[i].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