// #define _GLIBCXX_DEBUG // for STL debug (optional)
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;

#define debug(...) fprintf(stderr, __VA_ARGS__)
#define int long long int
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
typedef pair<int, int> pii;
typedef long long ll;
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const ll INF = 1001001001001001LL;
const ll MOD = 1000000007LL;

int mod_pow(int n, int k) {
    int res = 1;
    for(; k>0; k>>=1) {
        if(k & 1) (res *= n) %= MOD;
        (n *= n) %= MOD;
    }
    return res;
}

int calc(int teams) {
    int res = 1;
    for(int i=1; i<=2*teams; i++) {
        (res *= i) %= MOD;
    }
    for(int i=1; i<=teams; i++) {
        (res *= mod_pow(i, MOD-2)) %= MOD;
    }
    int inv2 = mod_pow(2, MOD-2);
    for(int i=1; i<=teams; i++) {
        (res *= inv2) %= MOD;
    }
    return res;
}

signed main() {
    int N, K; cin >> N >> K;
    vector<int> A(N);
    for(int i=0; i<N; i++) {
        cin >> A[i];
    }
    sort(A.rbegin(), A.rend());

    int ans = 1, idx = N-1;
    for(int i=0; i<N/2; i++) {
        if(A[i] + A[i+1] <= K) {
            int teams = (N - 2*i) / 2;
            (ans *= calc(teams)) %= MOD;
            break;
        }
        while(idx > i and A[i] + A[idx] <= K) {
            idx--;
        }

        if(idx == N-1) {
            ans = 0;
            break;
        }
        int rem = N - idx - 1;
        // fprintf(stderr, "i = %lld, idx = %lld, rem = %lld\n", i, idx, rem);
        (ans *= rem - i) %= MOD;
    }
    cout << ans << endl;
    return 0;
}