import sys,random,bisect
from collections import deque,defaultdict,Counter
from heapq import heapify,heappop,heappush
from itertools import cycle, permutations
from math import log,gcd

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

N,M = mi()
A = li()

S = {a%M:0 for a in A}
for a in A:
    a %= M
    S[a] += 1
    
res = 0
for a in S:
    if M-a not in S:
        res += S[a]
    else:
        if a < M-a:
            res += max(S[a],S[M-a])
        elif a==M-a:
            res += 1

print(res)