#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)

using std::cin;
using std::cout;
using std::min;
using std::max;
using std::set;
using std::map;
using std::vector;
using ll = long long;

int main() {
    int n; 
    ll m;
    cin >> n >> m;
    
    vector<ll> a(n);
    rep(i, n) cin >> a[i];
    rep(i, n) a[i] %= m;
    
    map<ll, int> mp;
    rep(i, n) mp[a[i]]++;
    
    set<ll> s;
    rep(i, n) {
        ll x = a[i];
        ll y = m-a[i];
        s.insert(min(x, y));
    }
    
    int ans = 0;
    for (ll x : s) {
        if (x == 0 or x*2 == m) ans++;
        else ans += max(mp[x], mp[m-x]);
    }
    
    cout << ans << '\n';
    
    return 0;
}