import sys
input = sys.stdin.readline

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

cnt=[0]*M
for a in A:
    cnt[a%M]+=1
ans=0
if cnt[0]>0:
    ans = 1

for i in range(1,(M+1)//2):
    if cnt[i] > cnt[M-i]:
        ans += cnt[i]
    else:
        ans += cnt[M-i]
if M%2==0 and cnt[M//2]>0:
    ans += 1
print(ans)