word_list = [[],[]]
initial = []
head_w = []
word_length = 0

for i in range(int(input())):
    word = input()
    word_list[0].append(word)
    initial.append(word[0])
    word_length += len(word)
for i in range(int(input())):
    word = input()
    word_list[1].append(word)
    if word[0] in initial:
        head_w.append(word[0])

if len(head_w)!=1:
    print(-1)
else:
    ans = head_w[0]
    choise_flag = 0
    while len(ans)!=word_length:
        tgt = ans[-1]
        for i,w in enumerate(word_list[choise_flag]):
            if tgt in w:
                ans += w[w.index(tgt)+1:]
                word_list[choise_flag].pop(i)
        choise_flag = (choise_flag+1)%2
    print(ans)