while True:
try:
lst = input().split()
words, x, k = lst[:-2], lst[-2], int(lst[-1])
bros = []
for w in words:
if len(w) == len(x) and w != x:
if sorted(w) == sorted(x):
bros.append(w)
print(len(bros))
if k <= len(bros):
print(sorted(bros)[k-1])
except:
break