#include<iostream>
#include<algorithm>
using namespace std;
long ans=1,mod=1e9+7;
int n,k,a[2<<17];
main()
{
	cin>>n>>k;
	for(int i=0;i<n;i++)cin>>a[i];
	sort(a,a+n);
	int id=n-1;
	for(int i=n;i-->n/2;)
	{
		if(id>=i)id=i-1;
		while(id>=0&&a[id]+a[i]>k)id--;
		if(id+1-(n-i-1)>0)ans=ans*(id+1-(n-i-1))%mod;
		else ans=0;
	}
	cout<<ans<<endl;
}