

import java.util.*;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();
		String output = "Yes";
		
		String[] W = new String[N];
		
		HashMap<String, Boolean> hmap = new HashMap<String, Boolean>();
		
		for(int i=0; i<N; i++) {
			W[i] = scanner.next();
			
			if(hmap.get(W[i]) != null)
				output = "No";
			hmap.put(W[i], true);
			
			if((i!=0) && (W[i].charAt(0) != (W[i-1].charAt(W[i-1].length()-1))))
				output = "No";
			
		}
		
		System.out.println(output);
		

	}

}

/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