//#include <bits/stdc++.h>
#include <iostream>
#include <complex>
#include <sstream>
#include <string>
#include <algorithm>
#include <deque>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <vector>
#include <set>
#include <limits>
#include <cstdio>
#include <cctype>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <ctime>
#include <climits>
#include <iomanip>

#define REP(i, n) for(int i = 0; i < (int)(n); i++)
#define FOR(i, j, k) for(int i = (int)(j); i < (int)(k); ++i)
#define ROF(i, j, k) for(int i = (int)(j); i >= (int)(k); --i)
#define FORLL(i, n, m) for(long long i = n; i < (long long)(m); i++)
#define SORT(v, n) sort(v, v+n)
#define REVERSE(v) reverse((v).begin(), (v).end())

using namespace std;
using ll = long long;
const ll MOD=1000000007LL;
typedef pair<int, int> P;

ll ADD(ll x, ll y) { return (x+y) % MOD; }
ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
ll MUL(ll x, ll y) { return x*y % MOD; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/ return MUL(x, POW(y, MOD-2)); }

template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}return 0;}

//解説AC
//https://yukicoder.me/submissions/318714


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;  
}

int
main(void){  
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  REP(i,n) cin >> a[i];
  sort(a.rbegin(), a.rend());

  int ans = 1;  
  int 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;
    (ans *= rem-i) %= MOD;
  }  
  cout << ans << endl;
  
  return 0;
}