题解 | #查找兄弟单词#

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

dic = {}
for i in danci:
    dic[i] = danci.count(i)

xd1 = []
xd = []
for item in beixuan:
    if len(item) == len(danci) and item != danci and set(item) == set(danci):
        xd1.append(item)

for item1 in xd1:
    x=1
    for i in item1:
        if item1.count(i) != dic[i]:
            x=0
    if x == 1:
        xd.append(item1)


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