#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++ (i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++ (i))
#define ALL(x) begin(x), end(x)
using ll = long long;
using namespace std;

template <int32_t MOD>
struct mint {
    int64_t value;
    mint() = default;
    mint(int64_t value_) : value(value_) {}
    inline mint<MOD> operator * (mint<MOD> other) const { int64_t c = this->value * int64_t(other.value) % MOD; return mint<MOD>(c < 0 ? c + MOD : c); }
    inline mint<MOD> & operator *= (mint<MOD> other) { this->value = this->value * int64_t(other.value) % MOD; if (this->value < 0) this->value += MOD; return *this; }
};

constexpr int MOD = 1e9 + 7;
mint<MOD> solve(int n, ll k, vector<ll> a) {
    sort(ALL(a));
    mint<MOD> acc = 1;
    int l = 0;
    REP (i, n / 2) {
        int r = n - i - 1;
        while (l < r and a[l] + a[r] <= k) ++ l;
        if (l >= r) {
            acc *= n - 2 * i - 1;
        } else {
            acc *= l - i;
        }

    }
    return acc;
}

int main() {
    int n; ll k; cin >> n >> k;
    vector<ll> a(n);
    REP (i, n) cin >> a[i];
    cout << solve(n, k, a).value << endl;
    return 0;
}