using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Runtime.Intrinsics.Arm;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, k) = (c[0], c[1]);
        var a = NList;
        var mod = 1_000_000_007;
        var over = new List<int>();
        var below = new List<int>();
        foreach (var ai in a)
        {
            if (ai > k / 2) over.Add(ai);
            else below.Add(ai);
        }
        over.Sort((l, r) => r.CompareTo(l));
        below.Sort();
        var ans = 1L;
        var pos = 0;
        var use = 0;
        foreach (var ai in over)
        {
            while (pos < below.Count && below[pos] + ai <= k) ++pos;
            ans = ans * (pos - use) % mod;
            ++use;
        }
        for (var i = below.Count - over.Count - 1; i >= 0; i -= 2) ans = ans * i % mod;
        WriteLine(ans);
    }
}