import sys
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
INF = 2 ** 63 - 1
mod = 998244353

from collections import Counter


n, m = mi() 

a = li()

C = Counter()

for v in a:
    C[v % m] += 1

ans = 0
s = set()
for c, v in C.items():
    if c in s: continue
    if m % 2 == 0 and c == m // 2:
        s.add(m // 2)
        ans += min(v, 1)
    else:
        if v > C[m - c]:
            s.add(c)
            ans += v
        else:
            s.add(m - c)
            ans += C[m - c]
    
print(ans)