#include<iostream>
#include<algorithm>
#include<cstdio>
using namespace std;
const int N=1e6+5;
int n,k,maxn,ans;
struct node{
	int x,id;
}a[N];
bool cmp(node a,node b){
	return a.x<b.x;
}
int f[N];
int tree[N];
int lowbit(int x){
	return x&(-x);
}
void add(int u,int val){
	if(!u){
		maxn=max(maxn,val);
		return;
	}
	for(int i=u;i<=n;i+=lowbit(i)) tree[i]=max(tree[i],val);
}
int query(int u){
	int ans=0;
	for(int i=u;i;i-=lowbit(i)) ans=max(ans,tree[i]);
	return ans;
}
int read(){
	int x=0;
	char c=getchar();
	while(c<'0'||c>'9') c=getchar();
	while(c>='0'&&c<='9'){
		x=x*10+c-48;
		c=getchar();
	}
	return x;
}
int main(){
	n=read();k=read();
	for(int i=1;i<=n;i++){
		a[i].x=read();
		a[i].id=i;
	}
	sort(a+1,a+n+1,cmp);
	int now=1;
	for(int i=1;i<=n;i++){
		if(a[i].id-a[i].x<0) continue;
		if(i!=1&&a[i].x!=a[i-1].x){
			while(now<i){
				if(a[now].id-a[now].x>=0) add(a[now].id-a[now].x,f[now]);
				now++;
			}
		}
		int tmp=max(maxn,query(a[i].id-a[i].x));
		f[i]=tmp+1;
		if(a[i].id-a[i].x<=k&&k<=n-a[i].x) ans=max(ans,f[i]);
	}
	cout<<ans<<endl;
	return 0;
}