k, l = list(map(int,input().split()))

z=[]

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

import itertools product_result = list(itertools.product(*z))

final_list=[]

def square(x): return (x**2)

for i in product_result: s=(sum(list(map(square,i)))) % l final_list.append(s)

print(max(final_list))