while True:
    try:
        s=input().split()
        l=[]
        for i in s[1:-2][:int(s[0])]:
            if i != s[-2] and sorted(i) == sorted(s[-2]):
                l.append(i)
        l.sort()
        print(len(l))
        print(l[int(s[-1])-1])
    except:
        break