#include <bits/stdc++.h>
using i64 = long long;

i64 pow(i64 x, i64 p, i64 mod) {
    i64 ret = 1;
    while (p) {
        if (p & 1) ret = ret * x % mod;
        x = x * x % mod;
        p >>= 1;
    }
    return ret;
}

i64 inv(i64 x, i64 mod) { return pow(x, mod - 2, mod); }

int main() {
    constexpr i64 mod = 1000000007;
    int n, k;
    std::cin >> n >> k;
    std::vector<int> a(n);
    for (auto &e : a) std::cin >> e;
    std::sort(a.begin(), a.end());
    i64 ret = 1, c = 0;
    for (int i = 0; i < n; i++) {
        while (c < n - 1 - i && a[c] + a[n - 1 - i] <= k) c++;
        ret = ret * (c - i) % mod;
        if (c == i) break;
        if (c == n - 1 - i) {
            auto r = c - i - 1;
            for (i64 j = r; j > 0; j -= 2) ret = j * (j - 1) / 2 % mod * ret % mod;
            if (r) {
                i64 f = 1;
                for (i64 j = 2; j <= r / 2; j++) f = f * j % mod;
                ret = ret * inv(f, mod) % mod;
            }
            break;
        }
    }
    std::cout << ret << std::endl;
    return 0;
}