from itertools import product

k,m = map(int, input().split())
listy = []

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

najw = 0
for i in product(*listy):
    wartosc = sum(x**2 for x in i)%m
    najw = max(najw, wartosc)

print(najw)