import java.io.*;
import java.util.*;
public class Main {
	
	public static void main(String[] args) {
	
		MyScanner sc = new MyScanner();
		
		//String s=sc.next();
		int n=sc.nextInt();
		String w[]=new String[n];
		String ans="Yes";
		for (int i = 0; i < n; i++) {
			String x=sc.next();
			if(i!=0) {
				int l=w[i-1].length();
			
				if(w[i-1].charAt(l-1)!=x.charAt(0)||Arrays.asList(w).contains(x)) {
					ans="No";
				}
				
			}
			
			w[i]=x;
		}
		System.out.println(ans);
		
		
	}	
	
	
	
//----------------------------------------------------------
	static int l_min(int[] a) {
		Arrays.sort(a);
		return a[0];
	}
	static int l_max(int[] a) {
		int l=a.length;
		Arrays.sort(a);
		return a[l-1];
	}
	public static PrintWriter out;

	public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String next() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		int nextInt() {
			return Integer.parseInt(next());
		}

		long nextLong() {
			return Long.parseLong(next());
		}

		double nextDouble() {
			return Double.parseDouble(next());
		}

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}

	}
	

}

/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