题解 | #查找兄弟单词#

count = 0
ls = []
res = ''
str = input().split()

head_num = str.pop(0)
k = int(str.pop())
x = str.pop()
for s in str:
    if s != x and (sorted(s)) == (sorted(x)):
        ls.append(s)
        count += 1
        if count == int(k): res = s
if count >= k:
    res = sorted(ls)[k - 1]
print(count)
print(res)