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];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

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

		int N = sc.nextInt();

		String[] W = new String[N];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

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

		int N = sc.nextInt();

		String[] W = new String[N];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

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

		int N = sc.nextInt();

		String[] W = new String[N];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc String[] W = new String[N]; W new String[N] N String[] chaf = new String[N]; chaf new String[N] N String[] chal = new String[N]; chal new String[N] N for(int i=0;i<N; i++) {
			W[i] = sc.next();
		} int i=0; int i=0; i 0 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 for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	} int i=0; int i=0; i 0 i<N i N i++ i++ i {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	} {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	} chal[i] = String.valueOf(W[i].charAt(W[i].length()-1)) chal[i] chal i String.valueOf(W[i].charAt(W[i].length()-1)) String.valueOf String 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 chaf[i] = String.valueOf(W[i].charAt(0)) chaf[i] chaf i String.valueOf(W[i].charAt(0)) String.valueOf String W[i].charAt(0) W[i].charAt W[i] W i 0 for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		} int i=0; int i=0; i 0 i<N i N i++ i++ i {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		} {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		} for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			} int j=0; int j=0; j 0 j<N j N j++ j++ j {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			} {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			} if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				} i!=j i j {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				} if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					} W[i].equals(W[j]) W[i].equals W[i] W i W[j] W j {System.out.print("No");
						System.exit(0);
					} System.out.print("No") System.out.print System.out System System.out "No" System.exit(0) System.exit System 0 for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		} int i=0; int i=0; i 0 i<N-1 i N-1 N 1 i++ i++ i {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		} {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		} if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			} chal[i].equals(chaf[i+1]) chal[i].equals chal[i] chal i chaf[i+1] chaf i+1 i 1 {		} {System.out.print("No");
			System.exit(0);
			} System.out.print("No") System.out.print System.out System System.out "No" System.exit(0) System.exit System 0 System.out.print("Yes") System.out.print System.out System System.out "Yes" String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int N = sc.nextInt();

		String[] W = new String[N];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

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

		int N = sc.nextInt();

		String[] W = new String[N];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

}
} Main
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];

		String[] chaf = new String[N];

		String[] chal = new String[N];

		for(int i=0;i<N; i++) {
			W[i] = sc.next();
		}



		for(int i=0;i<N; i++) {
		chal[i] = String.valueOf(W[i].charAt(W[i].length()-1));
		chaf[i] = String.valueOf(W[i].charAt(0));
	}

		for(int i=0;i<N;i++) {
			for(int j=0;j<N;j++) {
				if(i!=j) {
					if(W[i].equals(W[j])) {System.out.print("No");
						System.exit(0);
					}

				}
			}
		}

		for(int i=0; i<N-1; i++) {
			if(chal[i].equals(chaf[i+1])) {		}
			else {System.out.print("No");
			System.exit(0);
			}
		}

		System.out.print("Yes");

}
}
