#include <bits/stdc++.h>
using namespace std;

int main() {
	long long N, M; cin >> N >> M;
	vector<long long> A(N);
	for (int i = 0; i < N; i++) cin >> A[i];

	map<long long, long long> Map;
	set<long long> Set;
	for (int i = 0; i < N; i++) {
		Map[A[i] % M]++;
		Set.insert(A[i] % M);
	}

	long long count = 0;
	while (!Set.empty()) {
		long long a = *Set.begin();
		Set.erase(Set.begin());
		if (a == 0 || a * 2 == M) {
			count++;
		}
		else if (a * 2 < M) {
			count += max(Map[a], Map[M - a]);
		}
	}

	cout << count << endl;
}