#include <bits/stdc++.h> using namespace std; #ifdef LOCAL #include "xdebug.h" #else #define debug(...) 42 #endif #define st first #define nd second #define pb push_back #define all(x) (x).begin(), (x).end() #define BOOST ios_base::sync_with_stdio(0), cin.tie(0) template<typename T> using vc = vector<T>; using ll = long long; using ld = long double; using ii = pair<int, int>; const int mod = 1e9 + 9; void solve(){ int n, d; cin >> n >> d; vector<int> t(n); for(int i=0; i<n; i++){ cin >> t[i]; } sort(all(t)); ll ans = 1; int p = 0; for(int i=0; i<n; i++){ while(t[p] + d < t[i]) p++; ans *= (i-p+1); } cout << ans << "\n"; } int main(){ BOOST; int q = 1; // cin >> q; while(q--){ solve(); } }