import java.util.*;
public class Main {
	
	public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	}
} import java.util.*; util.* java public class Main {
	
	public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	}
} Main public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	} main {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc List<String> list = new ArrayList<>(N); list new ArrayList<>(N) String fast = sc.next(); fast sc.next() sc.next sc list.add(fast) list.add list fast char last = fast.charAt(fast.length() - 1); last fast.charAt(fast.length() - 1) fast.charAt fast fast.length() - 1 fast.length() fast.length fast 1 for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		} int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		} {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		} String w = sc.next(); w sc.next() sc.next sc if (list.contains(w)) {
				System.out.println("No");
				return;
			} list.contains(w) list.contains list w {
				System.out.println("No");
				return;
			} System.out.println("No") System.out.println System.out System System.out "No" return; list.add(w) list.add list w char last_c = w.charAt(w.length() - 1); last_c w.charAt(w.length() - 1) w.charAt w w.length() - 1 w.length() w.length w 1 if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			} last != w.charAt(0) last w.charAt(0) w.charAt w 0 {
				System.out.println("No");
				return;
			} System.out.println("No") System.out.println System.out System System.out "No" return; last = last_c last last_c System.out.println("Yes") System.out.println 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();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	}
} public class Main {
	
	public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	}
} Main
import java.util.*;
public class Main {
	
	public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		List<String> list = new ArrayList<>(N);
		
		String fast = sc.next();
		list.add(fast);
		
		char last = fast.charAt(fast.length() - 1);
		for (int i = 1; i < N; i++) {
			String w = sc.next();
			if (list.contains(w)) {
				System.out.println("No");
				return;
			}
			list.add(w);
			
			char last_c = w.charAt(w.length() - 1);
			if (last != w.charAt(0)) {
				System.out.println("No");
				return;
			}
			
			last = last_c;
		}
		
		System.out.println("Yes");
	}
}