from collections import Counter


def main():
    N, M = map(int, input().split())
    modulo_list = map(lambda num: int(num) % M, input().split())

    modulo_counter = Counter(modulo_list)

    element_sum = 0

    if modulo_counter[0] > 0:
        element_sum += 1
    if M % 2 == 0 and modulo_counter[M // 2] > 0:
        element_sum += 1

    for num in range(1, (M+1)//2):
        if modulo_counter[num] > modulo_counter[M-num]:
            element_sum += modulo_counter[num]
        else:
            element_sum += modulo_counter[M-num]

    print(element_sum)


if __name__ == "__main__":
    main()