#include <bits/stdc++.h>   using namespace std;   int main(void) {     ios::sync_with_stdio(false);     register int i;     register priority_queue<int> Queue;     register int N, T;     cin >> N >> T;     register int Ans;     Ans = 0;     for (i = 1; i <= N; i += 1) {       while (!Queue.empty() && Queue.top() >= T - i) {         Queue.pop();       }       register int X;       cin >> X;       if (max(X, i) < T) {         Queue.push(X - i);       }       Ans = max(Ans, (int)Queue.size());     }     cout << Ans << endl;     return 0;   }   