python

while True:
    try:
        line = str(input()).split(" ")
        num_word = int(line[0])
        word_list=[]
        for i in range(num_word):
            word_list.append(line[i+1])
        word_search = line[-2]
        kth = int(line[-1])
        brother_list=[]
        length = len(word_search) #搜索单词的长度
        for word in word_list:
            if len(word) == length and word != word_search:
                check = True
                for character in word:
                    if word.count(character)!= word_search.count(character):
                        check = False
                        break
                if check == True:
                    brother_list.append(word)

        brother_list.sort()
        print(len(brother_list))
        if kth <=len(brother_list):
            print(brother_list[kth-1])

    except:
        break