空间换时间

python的同学还是少，我就不详细写了，大家有疑问可以留言一起讨论哦

n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))

#a.sort()
b.sort()
c.sort()

def find(x, l, r, arr):
    while l < r:
        mid = l + r >> 1
        if arr[mid] > x: r = mid
        else: l = mid + 1
    return l

ans = 0
cnt = [0] * n
s = [0] * (n + 1)
for i in range(n):
    pos = find(b[i], 0, n, c)
    cnt[i] = n - pos
for i in range(n - 1 , -1, -1):
    s[i] = s[i + 1] + cnt[i]

for i in range(n):
    tmp = find(a[i], 0, n, b)
    ans += s[tmp]
print(ans)