s = input().split()
n = int(s.pop(0))
k = int(s.pop())

std = s.pop()
res =[]
for x in s:
    if x == std:
        continue
    elif sorted(std)==sorted(x):
        res.append(x)

res.sort()



print(len(res))
if len(res)>k:
    print(res[k-1])