line = input().split(" ")

n = int(line[0])
x = line[n+1]
k = int(line[-1])

ans = []
for i in range(1, 1+n, 1):
    word = line[i]
    if word != x and sorted(word) == sorted(x):
        ans.append(word)
    
print(len(ans))
if len(ans) > k:
    print(sorted(ans)[k-1])