import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    }
    
    System.out.println(ans);

  }
} import java.util.*; util.* java public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    }
    
    System.out.println(ans);

  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    }
    
    System.out.println(ans);

  } main {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        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 ans = "Yes"; ans "Yes" Set<String> set = new HashSet<>(); set new HashSet<>() String w = sc.next(); w sc.next() sc.next sc set.add(w) set.add set w char siri = w.charAt(w.length()-1); siri w.charAt(w.length()-1) w.charAt w w.length()-1 w.length() w.length w 1 for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    } int i = 0 ; int i = 0 ; i 0 i < n-1 i n-1 n 1 ++i ++i i {
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    } {
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    } w = sc.next() w sc.next() sc.next sc if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      } set.add(w) && siri==w.charAt(0) set.add(w) set.add set w siri==w.charAt(0) siri w.charAt(0) w.charAt w 0 {
        siri = w.charAt(w.length()-1);
        set.add(w);
      } siri = w.charAt(w.length()-1) siri w.charAt(w.length()-1) w.charAt w w.length()-1 w.length() w.length w 1 set.add(w) set.add set w {
        ans = "No";
      } ans = "No" ans "No" System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    }
    
    System.out.println(ans);

  }
} public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    }
    
    System.out.println(ans);

  }
} Main
import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    String ans = "Yes";

    Set<String> set = new HashSet<>();
    String w = sc.next();
    set.add(w);
    char siri = w.charAt(w.length()-1);
    

    for(int i = 0 ; i < n-1 ; ++i){
      w = sc.next();
      if(set.add(w) && siri==w.charAt(0)){
        siri = w.charAt(w.length()-1);
        set.add(w);
      }else{
        ans = "No";
      }
    }
    
    System.out.println(ans);

  }
}