input()
w = list(map(lambda x: (int(x), 1), input().split()))
input()
b = list(map(lambda x: (int(x), 0), input().split()))
c = -1
r = 0
o = 0
for p in sorted(w+b, key=lambda p: p[0]):
    if p[1] != c and p[0] > o:
        c = p[1]
        r += 1
        o = p[0]
print(r)