#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll N_MAX = 2e5;

int main(){
    ll n, m;
    cin >> n >> m;

    vector<ll> a(n);
    rep(i, n) cin >> a[i];

    map<ll, ll> mp;
    rep(i, n) mp[a[i]%m]++;

    ll ans = 0;
    for(auto itr=mp.begin(); itr!=mp.end(); itr++){
        if ((*itr).fi == 0 || (*itr).fi * 2 == m){
            ans++;
        }else{
            ans += max((*itr).se, mp[(m-(*itr).fi)%m]);
            (*itr).se = 0;
            mp[(m-(*itr).fi)%m] = 0;
        }
    }

    cout << ans << endl;
}