#include<bits/stdc++.h>
using namespace std;
//#include <atcoder/all>
//using namespace atcoder;
using ll = long long;
using P = pair<int,int>;
using Pll = pair<ll,ll>;
using Graph = vector<vector<int>>;
#define rep(i, n) for (ll i = 0; i < (n); ++i)
#define rep1(i,n) for(ll i = 1; i <= (n); ++i)
#define drep(i,n) for(ll i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (ll i = s; i < (t); ++i)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()

void solve(){
    ll n,m;
    cin >> n >> m;
    map<ll,ll> mp;
    rep(i,n){
        ll a;
        cin >> a;
        mp[a%m]++;
    }
    ll ans = 0;
    for(auto x : mp){
        if(2*x.first%m == 0){
            ans++;
            continue;
        }
        if(!mp.count((m-x.first)%m)){
            ans += x.second;
            continue;
        }
        ll y = (m-x.first)%m;
        if(x.first > y) continue;
        ans += max(mp[x.first],mp[y]); 
    }
    cout << ans << endl;
}

int main(void){
    solve();
    return 0;
}