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 s = "Yes";
		Set<String> set = new HashSet<>();
		String w = sc.next();
		set.add(w);
		char e = w.charAt(w.length()-1);

		for(int i=0; i<N-1; i++) {
			w = sc.next();
			if(set.add(w) && e==w.charAt(0)){
				e = w.charAt(w.length()-1);
		        set.add(w);
		     }else{
		        s = "No";
		      }
		}
		sc.close();
		System.out.println(s);
	}

}
/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