题解 | #查找兄弟单词#

shuru = input()
k = shuru.split(' ')[-1]
danci = shuru.split(' ')[-2]
beixuan = shuru.split(' ')[1:-2]


xd=[]
for item in beixuan:
    if len(item) == len(danci) and item != danci and sorted(item)==sorted(danci):
        xd.append(item)

print(len(xd))
xd.sort()
if len(xd) >= int(k):
    print(xd[int(k)-1])