#include <bits/stdc++.h>

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = std::int64_t;
using P = std::tuple<int,int>;

int N, K;
int A[200100];

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    std::cin >> N >> K;

    for(int i=0;i<N;++i){
        std::cin >> A[i];
    }

    std::sort(A, A + N);

    int cur = 0;
    ll cnt = 1;
    constexpr ll MOD = 1'000'000'007;
    for(int i=N-1;i>=N/2;--i){
        while(A[cur] + A[i] <= K){
            cur += 1;
        }

        cnt = cnt * std::max(std::min(cur, i) - (N - 1 - i), 0) % MOD;
    }

    std::cout << cnt << std::endl;
}