/* ---------- STL Libraries ---------- */
// IO library
#include <cstdio>
#include <fstream>
#include <iomanip>
#include <ios>
#include <iostream>

// algorithm library
#include <algorithm>
#include <cmath>
#include <numeric>
#include <random>
#include <cstring>

// container library
#include <array>
#include <bitset>
#include <deque>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <string>
#include <tuple>
#include <vector>
#include <stack>

/* ---------- Namespace ---------- */
using namespace std;

/* ---------- Type ---------- */
using ll = long long;
#define int ll
#define P pair<ll, ll>

/* ---------- Constants  */
const double PI = 3.141592653589793238462643383279;
const ll MOD = 1e9 + 7;
const int INF = 1LL << 55;

/* v-v-v-v-v-v-v-v-v Main Part v-v-v-v-v-v-v-v-v */
signed main() {
    int N, K;
    cin >> N >> K;
    int A[N];
    for (int i = 0; i < N; i++) cin >> A[i];
    sort(A, A + N);

    int ptr = -1;
    int ret = 1;
    int cnt = 0;
    for (int i = N - 1; i >= N/2; i--) {
        while (A[i] + A[ptr + 1] <= K && ptr < i - 1) ptr++;

        if (ptr >= i) {
            ret *= (i - cnt) % MOD;
        } else {
            ret *= (ptr + 1 - cnt) % MOD;
        }

        ret %= MOD;
        cnt++;
    }

    cout << ret << endl;

    return 0;
}