n,m = map(int,input().split())
a = list(map(int,input().split()))
from collections import defaultdict
m_d = defaultdict(int)
for i in range(n):
    m_d[a[i]%m] += 1
max_ = 0

for key in m_d.keys():
    if key == 0:continue
    if not (m&1) and key ==  m//2:continue
    max_ += m_d[key]
    
ans = 0
if m_d[0]:ans += 1
if not (m&1) and m_d[m//2]:ans+1
memo = set()
for key in list(m_d.keys())[::]:
    if key == 0:continue
    if not (m&1) and key ==  m//2:continue
    if key in memo:continue
    ans += max(m_d[key], m_d[m-key])
    memo.add(m-key)
print(ans)