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

d = defaultdict(int)

for num in a:
    d[num] += 1

ans = 0
for num in a:
    if num != 0:
        ans += max(d[num],d[m-num])
    d[num] = 0
    d[m-num] = 0

if 0 in a:
    ans += 1

print(ans)