from itertools import product

K, M= list(map(int, input().split()))
inp= [list(map(int, input().split()))[1::] for _ in range(K)]

super_squared_elements = []
for i in inp:
    squared_elements = []
    for j in i:
        squared_elements.append(j*j)
    super_squared_elements.append(squared_elements)
  
cartesian_product= list(product(*super_squared_elements))

max_check_appended= []

for val in cartesian_product:
    max_check_appended.append(sum(val) % M)

print(max(max_check_appended))