#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    ll N, M, ans=0, A;
    cin >> N >> M;
    map<ll, ll> mp;
    for (int i=0; i<N; i++){
        cin >> A; A %= M;
        mp[A]++;
        mp[M-A]+=0;
    }

    for (auto [x, y] : mp){
        if (x*2 > M) break;
        else if (x == 0 || x*2 == M) ans++;
        else{
            ans += max(mp[x], mp[M-x]);
        }
    }

    cout << ans << endl;

    return 0;
}