using System;
using System.Collections.Generic;
using System.Linq;

namespace yukicoder
{
    public class Program
    {
        public static void Main()
        {
            var line = Console.ReadLine().Split(' ');
            var n = int.Parse(line[0]);
            var x = int.Parse(line[1]);
            var a = Console.ReadLine().Split(' ').Select(value => int.Parse(value)).ToArray();
            var sum = 0;
            Array.Sort(a);
            for(var i = 0; i < n; i++)
            {
                for(var j = n - 1; j >= 0; j--)
                {
                    if (a[i] + a[j] == x)
                    {
                        sum++;
                    }
                    else if (a[i] + a[j] < x)
                    {
                        break;
                    }
                }
            }
            Console.WriteLine(sum);
        }
    }
}