#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;

const ll MOD = 1000000007LL;

int main(){
  int N;
  ll K;
  cin >> N >> K;
  vector<ll> v;
  rep(i,N){
    ll a;
    cin >> a;
    v.push_back(a);
  }

  sort(ALLOF(v));

  ll ret = 1;
  ll cnt = 0;
  for(int i=N-1; i>=N/2; i--){
    auto iter = upper_bound(ALLOF(v), K-v[i]);
    int j = iter - v.begin();
    if(j >= i) j = max(0,i);
    ret *= max(0LL, j - cnt);
    ret %= MOD;
    cnt++;
  }

  cout << ret << endl;
  
  return 0;
}