#include <bits/stdc++.h>
using namespace std;
using lint = long long;
int main() {
  lint n, m;
  cin >> n >> m;
  vector<lint> vec(n);
  for (int i = 0; i < n; i++) cin >> vec[i];
  map<lint, lint> ma;
  map<lint, lint> ma2;
  for (int i = 0; i < n; i++) {
    if (vec[i]%m == 0) ma2[vec[i]]++;
    else ma[vec[i]%m]++;
  }
  lint ans = 0;
  for (auto pa : ma) {
    lint x = pa.first;
    lint y = pa.second;
    if (m-x == x) ans++;
    else if (ma.count(m-x)) {
      if (m-x > x) ans += max(y, ma.at(m-x));
    }
    else ans += y;
    /*
    if (m-x == x) ans++;
    else if (m-x < x) break;
    else {
      if (ma.count(m-x)) {
        ans += max(ma.at(m-x), y);
      }
    }
    //*/
  }
  lint high = 0;
  for (auto x : ma2) high = max(high, x.second);
  cout << ans+high << endl;
}