import java.util.*;

class Main{

	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();
		String W = sc.next();
		 Set<String> list = new HashSet<String>();
		 list.add(W);
		 String ans = "Yes";

		for(int i = 1; i < N; i++){
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		}

		if(list.size() != N){
			ans = "No";
		}

		System.out.println(ans);


	}
} import java.util.*; util.* java class Main{

	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();
		String W = sc.next();
		 Set<String> list = new HashSet<String>();
		 list.add(W);
		 String ans = "Yes";

		for(int i = 1; i < N; i++){
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		}

		if(list.size() != N){
			ans = "No";
		}

		System.out.println(ans);


	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();
		String W = sc.next();
		 Set<String> list = new HashSet<String>();
		 list.add(W);
		 String ans = "Yes";

		for(int i = 1; i < N; i++){
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		}

		if(list.size() != N){
			ans = "No";
		}

		System.out.println(ans);


	} main {
		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();
		String W = sc.next();
		 Set<String> list = new HashSet<String>();
		 list.add(W);
		 String ans = "Yes";

		for(int i = 1; i < N; i++){
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		}

		if(list.size() != N){
			ans = "No";
		}

		System.out.println(ans);


	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc String W = sc.next(); W sc.next() sc.next sc Set<String> list = new HashSet<String>(); list new HashSet<String>() list.add(W) list.add list W String ans = "Yes"; ans "Yes" for(int i = 1; i < N; i++){
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		} int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		} {
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		} String W1 = W; W1 W String W2 = sc.next(); W2 sc.next() sc.next sc if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			} W1.charAt(W.length() - 1) == W2.charAt(0) W1.charAt(W.length() - 1) W1.charAt W1 W.length() - 1 W.length() W.length W 1 W2.charAt(0) W2.charAt W2 0 {
				W = W2;
				list.add(W);
			} W = W2 W W2 list.add(W) list.add list W {
				ans = "No";
				break;
			} ans = "No" ans "No" break; if(list.size() != N){
			ans = "No";
		} list.size() != N list.size() list.size list N {
			ans = "No";
		} ans = "No" ans "No" System.out.println(ans) System.out.println System.out System System.out ans String[] args args
import java.util.*;

class Main{

	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();
		String W = sc.next();
		 Set<String> list = new HashSet<String>();
		 list.add(W);
		 String ans = "Yes";

		for(int i = 1; i < N; i++){
			String W1 = W;
			String W2 = sc.next();
			if(W1.charAt(W.length() - 1) == W2.charAt(0)){
				W = W2;
				list.add(W);
			}else{
				ans = "No";
				break;
			}
		}

		if(list.size() != N){
			ans = "No";
		}

		System.out.println(ans);


	}
}