题解 | #查找兄弟单词#

# from collections import Counter


def counter(word: str):
    cnt = [0 for _ in range(26)]
    for char in word:
        cnt[ord(char) - ord("a")] += 1
    return cnt


if __name__ == "__main__":
    line = list(input().strip().split())
    n = int(line[0])
    k = int(line[-1])
    x = line[-2]
    words = list(line[1:-2])
    bros = list()
    for word in words:
        if word != x and sorted(word) == sorted(x):
            bros.append(word)
    bros.sort()
    print(len(bros))
    if len(bros) >= k:
        print(bros[k - 1])