import java.util.Scanner;
class Main{
    public static void main(String arg[]){
        Scanner scn=new Scanner(System.in);
        int n=scn.nextInt();
        String[] words=new String[n];
        for(int i=0;i<n;i++){
            words[i]=scn.next();
        }
        int flag=0;
        char b='a';
        for(int i=0;i<n;i++){
            char a=words[i].charAt(0);
            if(i>0&&a!=b){
                flag++;
                break;
            }
            b=words[i].charAt(words[i].length()-1);
            int f=0;
            for(int j=i+1;j<n;j++){
                if(words[i].equals(words[j])){
                    f++;
                    break;
                }
            }
            if(f>0){
                flag++;
                break;
            }
        }
        if(flag>0){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }
    }
}
/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