from itertools import product
k, m = list(map(int, input().split()))

# f(X) function
def f(x):
    return x**2

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

# Apply f(X) function
sqared_list = [[f(x) for x in l] for l in lst]

# Generate cartesian product to obtain all possible combinations
combined = product(*sqared_list)
max_s = 0
for c in combined:
    # Get local sum
    local_sum = sum(c)
    
    # Get local mod of m
    local_mod = local_sum % m
    
    # Get the maximized value
    max_s = max(max_s, local_mod)
print(max_s)