from collections import defaultdict
n,m = map(int,input().split())
a = list(map(int,input().split()))
amod = [num%m for num in a]

d = defaultdict(int)
db = defaultdict(bool)
d0 = defaultdict(int)
for idx,num in enumerate(amod):
    if num == 0:
        d0[a[idx]] += 1
    else:
        d[num] += 1
        db[num] = True

ans = 0
for num in amod:
    if num != 0 and db[num]:
        db[num] = False
        db[m-num] = False
        ans += max(d[num],d[m-num])


max0 = 0
for idx , num in enumerate(amod):
    if num == 0:
        max0 = max(max0 , d0[a[idx]])

print(ans + max0)