Problem:
The season for Snuke Festival has come again this year. First of all, Ringo will perform a ritual to summon Snuke. For the ritual, he needs an altar, which consists of three parts, one in each of the three categories: upper, middle and lower.  He has N parts for each of the three categories. The size of the i-th upper part is A_i, the size of the i-th middle part is B_i, and the size of the i-th lower part is C_i.  To build an altar, the size of the middle part must be strictly greater than that of the upper part, and the size of the lower part must be strictly greater than that of the middle part. On the other hand, any three parts that satisfy these conditions can be combined to form an altar.  How many different altars can Ringo build? Here, two altars are considered different when at least one of the three parts used is different.

Incorrect submission (verdict: Wrong Answer):
##a = int(stdin.readline().rstrip())
##b, c = [int(x) for x in stdin.readline().rstrip().split()]
##s = stdin.readline().rstrip()

##a = list(map(int,[int(x) for x in stdin.readline().rstrip().split()])) a[0, 1, 2, ...]
##a = [[0] * 2 for _ in range(n)]  a[0,0]






# -*- coding: utf-8 -*-
from sys import stdin
from operator import itemgetter
from collections import deque, Counter
import math
import pprint
from functools import reduce
import numpy as np
import random
import bisect



MOD = 1000000007
INF = float('inf')
alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]

def keta(kazu): 
    kazu_str = str(kazu)
    kazu_list = [int(kazu_str[i]) for i in range(0, len(kazu_str))]
    return kazu_list

def gcd(*numbers): 
    return reduce(math.gcd, numbers)

def combination(m,n): # mCn
    
    if n > m:
        return 'すまん'
    return math.factorial(m) // (math.factorial(m-n) * math.factorial(n))

def pow_k(x,n):  
    if n == 0:
        return 1
    K = 1
    while n > 1:
        if n % 2 != 0:
            K *= x
        x *= x
        n //= 2
    return K * x

def fact(n): 
    arr = {}
    temp = n
    for i in range(2,int(n**0.5)+1):
        if temp % i == 0:
            cnt = 0
            while temp % i == 0:
                cnt += 1
                temp //= i
            arr[i] = cnt
    if temp != 1:
        arr[temp] = 1
    if arr == {}:
        arr[n] = 1
    return arr


    
def main():
    n = int(stdin.readline().rstrip())
    a_kari = list(map(int,[int(x) for x in stdin.readline().rstrip().split()]))
    a = sorted(a_kari)
    b_kari = list(map(int,[int(x) for x in stdin.readline().rstrip().split()]))
    b = sorted(b_kari)
    c_kari = list(map(int,[int(x) for x in stdin.readline().rstrip().split()]))
    c = sorted(c_kari)
    board_ab = [0] * n
    board_bc = [0] * n
    ans = 0
    
    for i in range(n):
        ab = bisect.bisect_left(a, b[i])
        bc = n - bisect.bisect_right(c, b[i])
        ans += ab * bc
        print(ab,bc)
    print(ans)
    
main()

Fixed, accepted submission:
##a = int(stdin.readline().rstrip())
##b, c = [int(x) for x in stdin.readline().rstrip().split()]
##s = stdin.readline().rstrip()

##a = list(map(int,[int(x) for x in stdin.readline().rstrip().split()])) a[0, 1, 2, ...]
##a = [[0] * 2 for _ in range(n)]  a[0,0]






# -*- coding: utf-8 -*-
from sys import stdin
from operator import itemgetter
from collections import deque, Counter
import math
import pprint
from functools import reduce
import numpy as np
import random
import bisect



MOD = 1000000007
INF = float('inf')
alpha = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]

def keta(kazu): 
    kazu_str = str(kazu)
    kazu_list = [int(kazu_str[i]) for i in range(0, len(kazu_str))]
    return kazu_list

def gcd(*numbers): 
    return reduce(math.gcd, numbers)

def combination(m,n): # mCn
    
    if n > m:
        return 'すまん'
    return math.factorial(m) // (math.factorial(m-n) * math.factorial(n))

def pow_k(x,n):  
    if n == 0:
        return 1
    K = 1
    while n > 1:
        if n % 2 != 0:
            K *= x
        x *= x
        n //= 2
    return K * x

def fact(n): 
    arr = {}
    temp = n
    for i in range(2,int(n**0.5)+1):
        if temp % i == 0:
            cnt = 0
            while temp % i == 0:
                cnt += 1
                temp //= i
            arr[i] = cnt
    if temp != 1:
        arr[temp] = 1
    if arr == {}:
        arr[n] = 1
    return arr


    
def main():
    n = int(stdin.readline().rstrip())
    a_kari = list(map(int,[int(x) for x in stdin.readline().rstrip().split()]))
    a = sorted(a_kari)
    b_kari = list(map(int,[int(x) for x in stdin.readline().rstrip().split()]))
    b = sorted(b_kari)
    c_kari = list(map(int,[int(x) for x in stdin.readline().rstrip().split()]))
    c = sorted(c_kari)
    board_ab = [0] * n
    board_bc = [0] * n
    ans = 0
    
    for i in range(n):
        ab = bisect.bisect_left(a, b[i])
        bc = n - bisect.bisect_right(c, b[i])
        ans += ab * bc
        # print(ab,bc)
    print(ans)
    
main()