s = input().split(" ")

nums = int(s[0])
dics = s[1:nums + 2]
words, ks = s[-2], int(s[-1])

def checkbro(dic, word, k):
    count = 0
    dic_bro = []
    dic_bro_sort = []
    for i in range(len(dic)):
        if dic[i] != word:
            if sorted(dic[i]) == sorted(word):
                count += 1
                dic_bro.append(dic[i])
    dic_bro_sort = sorted(dic_bro)
    if k <= len(dic_bro_sort):
        return len(dic_bro), dic_bro_sort[k-1]
    else:
        return len(dic_bro), ''

result1, result2 = checkbro(dics,words,ks)
print(result1)
print(result2)