import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    }

    static class B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        }

        private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    }

    static class B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        }

        private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) B solver = new B(); solver new B() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        }

        private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        }

    } B public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        } solve {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        } int n = Integer.parseInt(in.next()); n Integer.parseInt(in.next()) Integer.parseInt Integer in.next() in.next in String w[] = new String[n]; w new String[n] n for (int i = 0; i < n; i++) {
                w[i] = in.next();
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                w[i] = in.next();
            } {
                w[i] = in.next();
            } w[i] = in.next() w[i] w i in.next() in.next in int ans = 0; ans 0 for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            } {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            } if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                } w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0) w[i - 1].charAt(w[i - 1].length() - 1) w[i - 1].charAt w[i - 1] w i - 1 i 1 w[i - 1].length() - 1 w[i - 1].length() w[i - 1].length w[i - 1] w i - 1 i 1 1 w[i].charAt(0) w[i].charAt w[i] w i 0 {
                    out.print("No");
                    return;
                } out.print("No") out.print out "No" return; if (isExist(i, w)) {
                    out.print("No");
                    return;
                } isExist(i, w) isExist i w {
                    out.print("No");
                    return;
                } out.print("No") out.print out "No" return; out.println("Yes") out.println out "Yes" int testNumber testNumber Scanner in in PrintWriter out out private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        } isExist {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        } for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                if (s[i].equals(s[n])) {
                    return true;
                }
            } {
                if (s[i].equals(s[n])) {
                    return true;
                }
            } if (s[i].equals(s[n])) {
                    return true;
                } s[i].equals(s[n]) s[i].equals s[i] s i s[n] s n {
                    return true;
                } return true; true return false; false int n n String s[] s public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    }

    static class B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        }

        private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    }

    static class B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        }

        private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        B solver = new B();
        solver.solve(1, in, out);
        out.close();
    }

    static class B {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 入力
            int n = Integer.parseInt(in.next());
            String w[] = new String[n];
            for (int i = 0; i < n; i++) {
                w[i] = in.next();
            }
            int ans = 0;

            for (int i = 1; i < n; i++) {
                if (w[i - 1].charAt(w[i - 1].length() - 1) != w[i].charAt(0)) {
                    out.print("No");
                    return;
                }
                if (isExist(i, w)) {
                    out.print("No");
                    return;
                }
            }

            // 出力
            out.println("Yes");

        }

        private static boolean isExist(int n, String s[]) {
            for (int i = 0; i < n; i++) {
                if (s[i].equals(s[n])) {
                    return true;
                }
            }
            return false;
        }

    }
}

