from itertools import product

K, M = list(map(int, input().split()))

lists = []
for i in range(K):
    elements = list(map(int, input().split()))
    lists.append(elements[1:])
    
squared_totals = [[e**2 for e in lst] for lst in lists]
squared_products = product(*squared_totals)

max_s = -1
for prod in squared_products:
    prod = sum(prod) % M
    if prod > max_s:
        max_s = prod
print(int(max_s))