#include<bits/stdc++.h>
using namespace std;
#define open(x) freopen(x ".in", "r", stdin);freopen(x ".out", "w", stdout);
#define int long long
inline int read(){int f=1;int x=0;char c=getchar();while(c<'0'||c>'9'){if(c=='-'){f=-f;}c=getchar();}while(c>='0'&&c<='9'){x=(x<<1)+(x<<3)+(c^48);c=getchar();}return x*f;}
inline void wr(int x){if(x<0){putchar('-');x=-x;}if(x>9){wr(x/10);}putchar(x%10+'0');}
int ans[1000050];

inline int lowbit(int x){
	return x & -x;
}
int f[1000050];
int out = 0;
int n,k;
int cnt = 0;

struct node{
	int x , id;
	bool operator <(const node& y)const{
		if(id - x == y.id - y.x){
			return id < y.id;
		}
		else{
			return id - x < y.id - y.x;
		}
	}
}a[1000050],g[1000050];

inline void sum(int x,int v){
	while(x <= n){
		f[x] = max(v , f[x]);
		x+=lowbit(x);
	}
	return;
}

inline int ask(int x){
	int R = 0;
	while(x > 0){
		R = max(R , f[x]);
		x-=lowbit(x);
	}
	return R;
}

signed main(){
	//open("1");
	n = read();
	k = read();
	for(int i = 1 ; i <= n ; ++i){
		a[i].x = read();
		a[i].id = i;
	} 
	for(int  i = 1 ; i <=  n ;++i){
		if(a[i].id - a[i].x >= 0 && a[i].id - a[i].x <= k && a[i].x + k <= n){
			g[++cnt].x = a[i].x;
			g[cnt].id = a[i].id;
		}
	}
	sort(g + 1 , g + cnt + 1);
	for(int i = 1 ; i <= cnt ;++i){
		ans[i] = ask(g[i].x - 1) + 1;
		sum(g[i].x , ans[i]);
	} 
	wr(ask(n));
	return 0;
}