from itertools import product A, B = map(int, input().split(" "))

appended_list = [] for i in range (1, A+1): K = list(map(int, input().split(" "))) all_list= [n for n in K if n != K[0]] appended_list.append(all_list)

V = list(product(*(appended_list)))

greatest_value = 0 for j in V: add_num = 0 for l in j:
add_num = add_num+l2
current_value = add_num%B if current_value > greatest_value: greatest_value = current_value else: greatest_value = greatest_value

print(greatest_value)

Here's the other method but without taking any inputs for my convenience:

from itertools import product

A = [24, 48, 96]
B = [24, 48, 96, 24]

PRODUCT = 0
for X in product(A, B):
    TOTAL = sum(x**2 for x in X) % int(24)
    PRODUCT = max(TOTAL, PRODUCT)
    print(TOTAL, PRODUCT)
print(PRODUCT)

I couldn't find a single easy to understand way, So here is mine with extra comments to make it easier

K, M = map(int, input().split())
POSSIBLE = {0}
for i in range(K):
    count, *num = list(map(int, input().split())) #1st number in count, and rest in num denoted by *
    vals = {pow(x, 2, M) for x in num} #num will be squared and its MOD M result will be stored in vals
    POSSIBLE = {(a+v)%M for a in POSSIBLE for v in vals} #Every value in vals is added with every value in POSSIBLE and then MOD M on each, finally stored in POSSIBLE
print(max(POSSIBLE))

from itertools import product

num,num1=input().split()

list1=[]

for i in range(int(num)):

k,*list_value=list(map(int,input().split()))

list1.append(list_value)

max_value=0

for cury in product(*list1):

tatal_val=sum(x**2 for x in cury)%int(num1)

max_value=max(max_value,tatal_val) 

print(max_value)