from collections import defaultdict
n,m = map(int,input().split())
a = list(map(int,input().split()))
b = [num%m for num in a]

d = defaultdict(int)
ans = 0
for num in b:
    if num == 0:
        ans |= 1
    else:
        d[num] += 1

if m%2:
    for num in b:
        ans += max(d[num],d[m-num])
        d[num] = 0
        d[m-num] = 0
else:
    boo = False
    for num in b:
        if num * 2 == m:
            boo = True
            continue
        ans += max(d[num],d[m-num])
        d[num] = 0
        d[m-num] = 0
    if boo:
        ans += 1

print(ans)