#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long long m;
  cin >> n >> m;
  vector<long long> a(n);
  map<long long, int> mp;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    a[i] %= m;
    mp[a[i]]++;
  }
  long long ans = 0;
  bool ok1 = false;
  bool ok2 = false;
  map<long long, int> used;
  for (int i = 0; i < n; i++) {
    if (used[a[i]]) continue;
    if (a[i] * 2 == m) ok1 = true;
    else if (a[i] == 0) ok2 = true;
    else ans += max(mp[a[i]], mp[m - a[i]]);
    used[a[i]]++;
    used[m - a[i]]++;
  }
  ans += ok1 + ok2;
  cout << ans << endl;
  return 0;
}