N,M=map(int,input().split())
A=list(map(int,input().split()))
B=[[0,i] for i in range(M)]
for a in A:
	B[a%M][0]+=1
B.sort(reverse=True)
S=set()
ans=0
for c,v in B:
	if 2*v%M==0:
		ans+=(c>0)
		S.add(v)
	else:
		if v not in S:
			ans+=c
			S.add(v)
			S.add(M-v)
print(ans)