n = int(input())

chars = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q']

clubs = []

for _ in range(n):
    club = input()
    club_desc = 0
    for i, c in enumerate(chars):
        if c in club:
            club_desc += 1 << i
    clubs.append(club_desc)

# print(clubs)

pcc = input()

end = False

for l in range(1, 17):
    for pcc_i in range(len(pcc) - l + 1):
        cd = 0
        for i,c in enumerate(chars):
            if c in pcc[pcc_i:pcc_i+l]:
                cd += 1 << i
        # print(cd)
        for club in clubs:
            if club & cd == club:
                print(l)
                end = True
                # print("END")
                break
        if end == True:
            break
    if end == True:
        break