#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007

int main() {
    long long n, k; cin >> n >> k;
    vector<long long> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    sort(a.begin(), a.end());
    long long ans = 1; long long in = 0;
    for (long long i = n-1; i >= 0; i--) {
        for (in; in < min(n, i); in++) {
            if (a[in] > k - a[i]) break;
        }
        if (in < n-1-i) break;
        ans *= (in - (n-1-i));
        ans %= mod;
        if (i == in) in--;
    }
    cout << ans << endl;
    return 0; 
}