import sys
input = lambda: sys.stdin.readline().rstrip()
from collections import Counter

#  -----------------------  #

n, m = map(int, input().split())
A = list(map(lambda x: int(x)%m, input().split()))
cou = Counter(A)
ans = 0
st = set()
for k,v in cou.items():
  k %= m
  if k in st:
    continue

  if k == 0:
    ans += 1
    st.add(k)
  elif m % 2 == 0 and k == m//2:
    ans += 1
    st.add(k)
  else:
    ans += max(v, cou[m-k])
    st.add(m-k)
print(ans)