from itertools import product
Nw = int(input())
W = list(map(int, input().split()))
Nb = int(input())
B = list(map(int, input().split()))
data = []
for w in W:
    data.append((w, 0))
for b in B:
    data.append((b, 1))
data.sort()
N = Nw + Nb

ans = 0
for pat in product([0, 1], repeat=N):
    # 前と＝じゃないかだけ
    pre_color = -1
    pre_length = 0
    cnt = 0
    for i in range(N):
        if pat[i] == 1:
            cnt += 1
            length, color = data[i]
            if pre_color == color:
                break
            if pre_length == length:
                break

            pre_color = color
            pre_length = length
    else:
        ans = max(ans, cnt)

print(ans)