HackerRank Python - Maximize It

You have to pick one element from each list so that the value from the equation below is maximized:

# Enter your code here. Read input from STDIN. Print output to STDOUT

from itertools import product

k, m = map(int, input().split())

array = []
for _ in range(k):
    array.append(list(map(int, input().split()))[1:])

result = 0
for combination in product(*array):
    result = max(sum([x * x for x in combination]) % m, result)
print(result)