Buggy python submission (verdict: Runtime Error):
# coding: utf-8
n = int(input())
al = sorted(list(set(int(i) for i in input().split())))
bl = sorted(list(set(int(i) for i in input().split())))
cl = sorted(list(set(int(i) for i in input().split())))
ans = 0

def search(ar, key, flag):
    left = -1
    right = len(ar)
    center = (left + right) // 2
    
    while right - left > 1:
        if ar[center] == key:
            if flag == 0:
                return center
            elif flag == 1:
                return len(ar)-1-center
        elif ar[center] < key:
            left = center
            center = (left + right) // 2
        else:
            right = center
            center = (left + right) // 2
    
    if flag == 0:
        return right
    elif flag == 1:
        return len(ar) - right
        

for i in range(n):
    mid = bl[i]
    top_num = search(al, mid, 0)
    bottom_num = search(cl, mid, 1)
    ans += top_num * bottom_num
    
print(ans)

Fixed submission:
# coding: utf-8
n = int(input())
al = sorted(list(int(i) for i in input().split()))
bl = sorted(list(int(i) for i in input().split()))
cl = sorted(list(int(i) for i in input().split()))
ans = 0

def low_left(a, key):
    left = -1
    right = len(a)
    while right - left > 1:
        center = (left + right) // 2
        if a[center] >= key:
            right = center
        else:
            left = center
    return left+1 
    
def high_right(a, key):
    left = -1
    right = len(a)
    while right - left > 1:
        center = (left + right) // 2
        if a[center] <= key:
            left = center
        else:
            right = center
    return n-right
    
for i in bl:
    ans += low_left(al, i) * high_right(cl, i)

print(ans)

Buggy python submission (verdict: Runtime Error):
# coding: utf-8
# Your code here!
n = int(input())
al = sorted(set(int(i) for i in input().split()))
bl = sorted(set(int(i) for i in input().split()))
cl = sorted(set(int(i) for i in input().split()))
ans = 0

def search(ar, key, flag):
    left = -1
    right = len(ar)
    center = (left + right) // 2
    
    while right - left > 1:
        if ar[center] == key:
            if flag == 0:
                return center
            elif flag == 1:
                return len(ar)-1-center
        elif ar[center] < key:
            left = center
            center = (left + right) // 2
        else:
            right = center
            center = (left + right) // 2
    
    if flag == 0:
        return right
    elif flag == 1:
        return len(ar) - right
        

for i in range(n):
    mid = bl[i]
    top_num = search(al, mid, 0)
    bottom_num = search(cl, mid, 1)
    ans += top_num * bottom_num
    
print(ans)
        

Fixed submission:
# coding: utf-8
n = int(input())
al = sorted(list(int(i) for i in input().split()))
bl = sorted(list(int(i) for i in input().split()))
cl = sorted(list(int(i) for i in input().split()))
ans = 0

def low_left(a, key):
    left = -1
    right = len(a)
    while right - left > 1:
        center = (left + right) // 2
        if a[center] >= key:
            right = center
        else:
            left = center
    return left+1 
    
def high_right(a, key):
    left = -1
    right = len(a)
    while right - left > 1:
        center = (left + right) // 2
        if a[center] <= key:
            left = center
        else:
            right = center
    return n-right
    
for i in bl:
    ans += low_left(al, i) * high_right(cl, i)

print(ans)