a=input()
aa=[int(s) for s in input().split()]
b=input()
bb=[int(s) for s in input().split()]
c=input()
cc=[int(s) for s in input().split()]
sum=0
for i in aa:
    if i in bb and i in cc:
        sum+=1
print(sum)

aa = [1, 3, 1, 5, 7, 9]
bb = [1,2,3,4]
cc = [1,3,10]

chk = set(bb) & set(cc)
print(chk)
#{1, 3}

res = sum(x in chk for x in aa)
print(res)
#3

In [3]: %paste
from random import randint

N = 10**4
aa = [randint(0,1000) for _ in range(N)]
bb = [randint(0,10**7) for _ in range(N)]
cc = [randint(0,10**9) for _ in range(N)]
## -- End pasted text --

In [4]: %paste
%%timeit
sm=0
for i in aa:
    if i in bb and i in cc:
        sm+=1
## -- End pasted text --
3.74 s ± 46.6 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

In [5]: %paste
%%timeit
chk = set(bb) & set(cc)
res = sum(x in chk for x in aa)
## -- End pasted text --
5.16 ms ± 33.5 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

In [6]: 3.74 * 1000 / 5.16
Out[6]: 724.8062015503875