import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int n = Integer.parseInt(sa[0]);
		long m = Long.parseLong(sa[1]);
		sa = br.readLine().split(" ");
		long[] a = new long[n];
		for (int i = 0; i < n; i++) {
			a[i] = Long.parseLong(sa[i]);
		}
		br.close();

		Map<Long, Integer> map = new HashMap<>();
		for (int i = 0; i < n; i++) {
			long k = a[i] % m;
			map.put(k, map.getOrDefault(k, 0) + 1);
		}

		long m2 = m % 2 == 0 ? m / 2 : 0;
		int ans = 0;
		Set<Long> set = new HashSet<>();
		for (long key : map.keySet()) {
			int v1 = map.get(key);
			if (key == 0 || key == m2) {
				ans++;
			} else if (!set.contains(key)) {
				set.add(m - key);
				int v2 = map.getOrDefault(m - key, 0);
				ans += Math.max(v1, v2);
			}
			set.add(key);
		}
		System.out.println(ans);
	}
}