import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        long m = sc.nextLong();
        HashMap<Long, Integer> counts = new HashMap<>();
        for (int i = 0; i < n; i++) {
            long mod = sc.nextLong() % m;
            counts.put(mod, counts.getOrDefault(mod, 0) + 1);
        }
        int ans = 0;
        int half = 0;
        for (long x : counts.keySet()) {
            if (x + x == m || x == 0) {
                continue;
            }
            if (counts.containsKey(m - x)) {
                half += Math.max(counts.get(x), counts.getOrDefault(m - x, 0));
            } else {
                ans += counts.get(x);
            }
        }
        ans += half / 2;
        if (counts.containsKey(0L)) {
            ans++;
        }
        if (m % 2 == 0 && counts.containsKey(m / 2)) {
            ans++;
        }
        System.out.println(ans);
    }
}

class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}