import java.util.Scanner;

public class Main {

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}

} import java.util.Scanner; Scanner java.util public class Main {

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int n; n boolean ans=true; ans true String[] w = new String[101]; w new String[101] 101 n=sc.nextInt() n sc.nextInt() sc.nextInt sc for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		} int i=1; int i=1; i 1 i<=n i n i++ i++ i {
			w[i]=sc.next();
		} {
			w[i]=sc.next();
		} w[i]=sc.next() w[i] w i sc.next() sc.next sc char ch=w[1].charAt(w[1].length()-1); ch w[1].charAt(w[1].length()-1) w[1].charAt w[1] w 1 w[1].length()-1 w[1].length() w[1].length w[1] w 1 1 for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		} int i=2; int i=2; i 2 i<=n i n i++ i++ i {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		} {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		} if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			} ch==w[i].charAt(0) ch w[i].charAt(0) w[i].charAt w[i] w i 0 {
				ch=w[i].charAt(w[i].length()-1);
			} ch=w[i].charAt(w[i].length()-1) ch w[i].charAt(w[i].length()-1) w[i].charAt w[i] w i w[i].length()-1 w[i].length() w[i].length w[i] w i 1 {
				ans=false;
				break;
			} ans=false ans false break; if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		} ans {
			System.out.println("Yes");
		} System.out.println("Yes") System.out.println System.out System System.out "Yes" {
			System.out.println("No");
		} System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}

} public class Main {

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}

} Main
import java.util.Scanner;

public class Main {

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

		int n;
		boolean ans=true;
		String[] w = new String[101];

		n=sc.nextInt();

		for(int i=1;i<=n;i++) {
			w[i]=sc.next();
		}

		char ch=w[1].charAt(w[1].length()-1);

		for(int i=2;i<=n;i++) {
			if(ch==w[i].charAt(0)) {
				ch=w[i].charAt(w[i].length()-1);
			} else {
				ans=false;
				break;
			}
		}

		twho:for(int i=1;i<=n;i++) {
			for(int k=i+1;k<=n;k++) {
				if(w[i].equals(w[k])) {
					ans=false;
					break twho;
				}
			}
		}

		if(ans) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}

}
