/// *** --- ||| In the name of ALLAH ||| --- *** /// #include<bits/stdc++.h> using namespace std; #define fastio() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); #define fraction() cout.unsetf(ios::floatfield); cout.precision(10); cout.setf(ios::fixed,ios::floatfield); #define file() freopen("input.txt","r",stdin);freopen("output.txt","w",stdout); #define endl '\n' #define ll long long #define int long long #define all(a) (a).begin(),(a).end() #define rall(a) (a).rbegin(),(a).rend() #define sz(x) (int)x.size() #define mem(a,b) memset(a, b, sizeof(a) ) #define sq(a) ((a) * (a)) #define unq(x) {x.erase(unique(x.begin(),x.end()),x.end());} const double PI = acos(-1); const double eps = 1e-9; const int inf = 2000000000; const int MX = 2e5+123; const ll infLL = 9000000000000000000; const int MOD = 1e9+9; // //debug template<typename F,typename S>ostream&operator<<(ostream&os,const pair<F,S>&p){return os<<"("<<p.first<<", "<<p.second<<")";} template<typename T>ostream&operator<<(ostream&os,const vector<T>&v){os<<"{";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<", ";os<<*it;}return os<<"}";} template<typename T>ostream&operator<<(ostream&os,const set<T>&v){os<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<",";os<<*it;}return os<<"]";} template<typename T>ostream&operator<<(ostream&os,const multiset<T>&v) {os<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<", ";os<<*it;}return os<<"]";} template<typename F,typename S>ostream&operator<<(ostream&os,const map<F,S>&v){os<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())os<<", ";os<<it->first<<" = "<<it->second;}return os<<"]";} #define dbg(args...) do {cerr << #args << " : "; faltu(args); } while(0) void faltu(){cerr << endl;} template<typename T>void faltu(T a[],int n){for(int i=0;i<n;++i)cerr<<a[i]<<' ';cerr<<endl;} template<typename T,typename...hello>void faltu(T arg,const hello&...rest){cerr<<arg<<' ';faltu(rest...);} //#else //#define dbg(args...) // https://oj.uz/problem/view/CEOI10_tower void solve (int CaseNo) { int n, d; cin >> n >> d; vector<int> h(n); for (int i = 0; i < n; i++) cin >> h[i]; sort (all (h)); int ans = 1; for (int i = 0; i < n; i++) { int upperRange = h[i] + d; int mxIndex = upper_bound (all (h), upperRange) - h.begin() - 1; ans *= (mxIndex - i + 1); ans %= MOD; } cout << ans << endl; } int32_t main() { fastio(); // srand(time(NULL)); int testcases = 1; // cin >> testcases; for (int tt = 1; tt <= testcases; tt++) { solve (tt); } return 0; }