import sys
input = sys.stdin.readline
from collections import *

N, M = map(int, input().split())
A = list(map(int, input().split()))
cnt = defaultdict(int)

for Ai in A:
    cnt[Ai%M] += 1

ans = 0
s = set()
l = list(cnt.keys())

for k in l:
    if k in s:
        continue
    
    if k==0 or (M%2==0 and k==M//2):
        ans += min(1, cnt[k])
    else:
        ans += max(cnt[k], cnt[M-k])
        s.add(M-k)

print(ans)