n = int(input())

lines = []

for i in range(n):
    lines.append(input())

_all = input()

min_len = len(min(lines, key=len))
current_set = _all[:min_len]
length = len(_all)

current_len = min_len
i = current_len
while True:
    for line in lines:
        if all(i in current_set for i in line):
            print(len(current_set))
            exit()
    if i != length:
        current_set = current_set[1:]
        current_set += _all[i]
        i += 1
    else:
        i = current_len
        current_len += 1
        current_set = _all[:current_len]


# 2
# baf
# lek
# affleck