from itertools import *
from bisect import *
# from math import *
from collections import *
from heapq import *
from random import *
from decimal import *
import numpy as np
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def MI1(): return map(int1, sys.stdin.readline().split())
def MF(): return map(float, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LF(): return list(map(float, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
dij = [(0, 1), (1, 0), (0, -1), (-1, 0)]

def main():
    an=II()
    aa=[input() for _ in range(an)]
    n=sum(len(a) for a in aa)
    bn=II()
    bb=[input() for _ in range(bn)]
    to=defaultdict(str)
    for ss in [aa,bb]:
        for s in ss:
            for c0,c1 in zip(s,s[1:]):
                to[c0]=c1
    for a in aa:
        ans=a[0]
        cnt=1
        while to[ans[-1]]!="":
            ans+=to[ans[-1]]
            cnt+=1
        if cnt==n:
            print(ans)
            exit()
    print(-1)

main()