using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;
using System.Text;

public class Program
{

    public void Proc()
    {
        long[] inpt = Reader.ReadLine().Split(' ').Select(a => long.Parse(a)).ToArray();
        long total = inpt[1];

        long[] items = Reader.ReadLine().Split(' ').Select(a => long.Parse(a)).ToArray();

        Dictionary<long, int> dic = new Dictionary<long, int>();

        foreach(long item in items) {
            if(dic.ContainsKey(item)) {
                dic[item]++;
            } else {
                dic[item] = 1;
            }
        }

        long ans = 0;
        foreach(long key in dic.Keys) {
            long pairKey = total - key;
            if(pairKey<0) {
                continue;
            }
            if(!dic.ContainsKey(pairKey)) {
                continue;
            }
            ans += (long)dic[key] * (long)dic[pairKey];
        }
        Console.WriteLine(ans);

    }

    private int[] GetIntArray() {
        return Reader.ReadLine().Trim().Split(' ').Select(a => int.Parse(a)).ToArray();
    }


    public class Reader
    {
        static StringReader sr;
        public static bool IsDebug = false;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (sr == null)
                {
                    sr = new StringReader(InputText.Trim());
                }
                return sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        private static string InputText = @"






";
    }

    public static void Main(string[] args)
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}