from collections import defaultdict
n, m = map(int, input().split())
count = defaultdict(int)
for v in map(int, input().split()): count[v%m] += 1
ans = 0
check = set()
for k in list(count.keys()):
    if k*2%m == 0: ans += min(count[k], 1)
    elif k not in check:
        ans += max(count[k], count[m-k])
        check.add(m-k)
print(ans)