//ｺｯwwｺｯwwｺｹｯwwwｺｯwwｺｹｯwwwｺｹｯｺｯwwwｺｯwwｺｯwwｺｹｯwwwｺｯwwｺｹｯwwwｺｹｯｺｯwwwｺｹｰｰｰｰｯ!!!wwwwwｺｯwwｺｯwwｺｹｯwwwｺｯwwｺｹｯwwwｺｹｯｺｯwwwｺｯwwｺｯwwｺｹｯwwwｺｯwwwｺｹｯwwwｺｹｯｺｯwwwｺｹｰｰｰｰｯ!!!wwwwwｺｹｯｺｯｯｺｰｰｰｰ!!!!!!wwwwwwwwwww
import java.util.*;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String[] s = new String[n];
        for(int i = 0 ; i < n ; i++){
            s[i] = sc.next();
        }
        sc.close();
        boolean ebishu = true;
        for(int i = 1 ; i < n && ebishu ; i++){
            if(s[i - 1].charAt(s[i - 1].length() - 1) != s[i].charAt(0)) ebishu = false;
        }
        Arrays.sort(s);
        for(int i = 1 ; i < n && ebishu ; i++){
            if(s[i - 1].equals(s[i])) ebishu = false;
        }
        if(ebishu){
            System.out.println("Yes");
        }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