import java.util.ArrayList;
import java.util.Scanner;
public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String[]W = new String[n];
        ArrayList<String>ans  = new ArrayList<>();

    for(int i=0; i<n; i++) {
    	W[i] = sc.next();
    	if(!ans.contains(W[i])){		
    	      ans.add(W[i]);
    	}
    }
    int cou = 0;
    for(int i=0; i<n-1; i++) {
    	if(W[i].charAt(W[i].length()-1) != W[i+1].charAt(0)) {
    		cou++;
    	}
    }
    	if(ans.size() == n){
    		if(cou == 0) {
    		  	System.out.println("Yes");
    		}else {
    			System.out.println("No");
    		}
    	}else {
    			System.out.println("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