import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
n,m = na()
a = na()
from collections import defaultdict
c = defaultdict(int)
for i in range(n):
    c[a[i]%m] += 1

ans = 0
for i in list(c):
    if i== 0 or i * 2 == m:
        ans += 1
    else:
        ans += max(c[i], c[m-i])
        c[i] = 0
        c[m-i] = 0
print(ans)