#include "bits/stdc++.h"

using namespace std;

const int MOD = 1e9+7;

void solve()
{
	int N, K;
	cin >> N >> K;
	vector<long> as(N);
	for (int i = 0; i < N; i++) cin >> as[i];
	sort(as.begin(), as.end());
	if (as.front() + as.back() > K)
	{
		cout << 0 << endl;
		return;
	}
	long ans = 1, res = N;
	for (int i = N-1; i >= 0; i--)
	{
		long a = as[i];
		if (a*2 <= K) break;
		auto it = upper_bound(as.begin(), as.end(), K-a);
		ans *= (long)(it-as.begin()-(N-i-1));
		ans %= MOD;
		res-=2;
	}
	for (;res; res -= 2)
	{
		ans *= res-1;
		ans %= MOD;
	}
	ans %= MOD;
	cout << ans << endl;
}

int main(void)
{
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}