nw = int(input())
W = list(map(int, input().split()))
nb = int(input())
B = list(map(int, input().split()))

def get_height(base, next_color):
    m = []
    i = max(base)
    m.append(i)
    while True:
        next_color = [k for k in next_color if k < i]
        if next_color == []:
            break
        i = max(next_color)
        m.append(i)
        base = [s for s in base if s < i]
        if base == []:
            break
        i = max(base)
        m.append(i)

    return len(m)

WC = W[:]
BC = B[:]

if __name__ == '__main__':

    white = get_height(WC, BC)
    black = get_height(BC, WC)
    print(max(white, black))