n, m = map(int, input().split())
A = list(map(int, input().split()))
A.sort()
cnt = {}
for a in A:
    a %= m
    cnt[a] = cnt.get(a, 0) + 1

keys = list(cnt.keys())
ans = 0
for k in keys:
    if k not in cnt:
        pass
    elif k == 0:
        ans += 1
    elif k * 2 == m:
        ans += 1
    elif m - k in cnt:
        ans += max(cnt[k], cnt[m - k])
        del cnt[m - k]
    else:
        ans += cnt[k]

print(ans)