## https://yukicoder.me/problems/no/1972

def main():
    N, M = map(int, input().split())
    A = list(map(int, input().split()))

    mod_m_map = {}
    for a in A:
        a_m = a % M
        if a_m not in mod_m_map:
            mod_m_map[a_m] = 0
        mod_m_map[a_m] += 1
    
    mod_m_pair_map = {}
    for key in mod_m_map.keys():
        o_key = M - key
        o_key %= M

        if key != o_key:
            v = mod_m_map[key]
            if o_key in mod_m_map:
                v = max(v, mod_m_map[o_key])

            new_key = (min(key, o_key), max(key, o_key))
            if new_key not in mod_m_pair_map:
                mod_m_pair_map[new_key] = v
        else:
            new_key = (key, key)
            if new_key not in mod_m_pair_map:
                mod_m_pair_map[new_key] = 1
    
    answer = sum(mod_m_pair_map.values())
    print(answer)










if __name__ == '__main__':
    main()