N =int(input())
Nl = []

for i in range(N):
    Nl.append(int(input()))

M = int(input())
Ml = []

for j in range(M):
    Ml.append(int(input()))

answerl = []


Nl = set(Nl)
Nl = list(Nl)
Nl.sort()

for ni in Nl:
    for mi in Ml:
        if mi == ni:
            answerl.append(mi)
        else:
            continue

print(len(answerl))

https://docs.python.org/3/library/stdtypes.html#set

x in s
    Test x for membership in s.