n = int(input())
words1 = [input() for _ in range(n)]

m = int(input())
words2 = [input() for _ in range(m)]

common_columns = set(words1) & set(words2)
max_length = 0
result = ""

for column in common_columns:
    if len(column) > max_length:
        max_length = len(column)
        result = column

if result:
    print(result)
else:
    print("-")