#include <bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 1e9 + 7;

int main() {
 int N, K, A[200000];
 cin >> N >> K;
 for(int i = 0; i < N; i++) cin >> A[i];
 sort(A, A + N);
 int64 ret = 1, ptr = 0, candidate = 0;
 for(int i = N - 1; i >= N / 2; i--) {
   while(ptr <= i && A[ptr] + A[i] <= K) {
     ++ptr;
     ++candidate;
   }
   if(i < ptr) --candidate;
   (ret *= candidate) %= mod;
   --candidate;
 }
 cout << ret << endl;
}