from itertools import product

k, m = map(int, input().split())
L, max_value = [], 0
for i in range(0, k):
    L.append(list(map(lambda x: int(x) ** 2, input().split()[1:])))

for i in product(*L):
    if max_value < (sum(i) % m):
        max_value = sum(i) % m
print(max_value)