lines = []
for i in range(int(input())):
    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
try:
    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:
            current_len += 1
            i = current_len
            current_set = _all[:current_len]
except:
    print(0)

# 2
# baf
# lek
# affleck