using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

​

        Console.WriteLine(CheckSorted(new string[]{"a","aa"}, "abcdefghijklmnopqrstuvwxyz"));

    }

    public static bool CheckSorted(string[] words, string order) {

        if (words.Length == 0) {

            return true;

        }

        var table = new Dictionary<char, int>();

        for(int i = 0; i < order.Length; i++) {

            table.Add(order[i], i + 1);

        }

        var priorSort = GetSortIndex(words[0], 0, table);

        for (int i = 1; i < words.Length; i++) {

            var wordSort = GetSortIndex(words[i], 0, table);

            if (wordSort < priorSort) {

                return false;

            }

            if (wordSort == priorSort) {

                for (int j = 1; j < Math.Min(words[i].Length, words[i-1].Length) + 1; j++) {

                    var priorWordSort = GetSortIndex(words[i-1], j, table);

                    var currWordSort = GetSortIndex(words[i], j, table);

                    if (currWordSort < priorWordSort) {

                        return false;

                    }

                    else if (currWordSort > priorWordSort) {

                        break;

                    }

                }

            }

        }

        return true;

    }

    private static int GetSortIndex(string word, int index, Dictionary<char, int> table) {

        return word.Length <= index ? 0 : table[word[index]];

    }

}