python

while True:
    try:
        line = input().split()
        num = int(line[0])
        initial = line[1:num+1]
        word = line[-2]
        k = int(line[-1])
        dic = []
        for w in initial:
            if w != word and sorted(w) == sorted(word):
                dic.append(w)
        dic.sort()
        print(len(dic))
        if len(dic) >= k:
            print(dic[k-1])
    except:
        break