using System; using static System.Console; using System.Linq; using System.Collections.Generic; class Program { static int NN => int.Parse(ReadLine()); static long[] NList => ReadLine().Split().Select(long.Parse).ToArray(); static void Main() { var c = NList; var (n, m) = ((int)c[0], c[1]); var a = NList; var dic = new Dictionary<long, int>(); foreach (var ai in a) { var mod = ai % m; if (dic.ContainsKey(mod)) ++dic[mod]; else dic[mod] = 1; } var res = 0; var delList = new HashSet<long>(); foreach (var kv in dic) { if (delList.Contains(kv.Key)) continue; if (kv.Key == 0) { ++res; continue; } else if (kv.Key * 2 == m) { ++res; continue; } var rev = dic.ContainsKey(m - kv.Key) ? dic[m - kv.Key] : 0; res += Math.Max(kv.Value, rev); delList.Add(m - kv.Key); } WriteLine(res); } }