from collections import defaultdict

n,m=map(int,input().split())
a=list(map(int,input().split()))
cnt=defaultdict(int)
s=set()
for i in a:
  cnt[i%m]+=1
  s.add(i%m)

ans=0
for i in s:
  if i==0:
    ans+=1
    
  elif i*2==m:
    ans+=1
  else:
    ans+=max(cnt[i],cnt[m-i])
    cnt[i],cnt[m-i]=0,0

print(ans)