#include <bits/stdc++.h>
#define el '\n'
#define FNAME "IMPARR"
#define allof(x) x.begin(),x.end()
#define allof1(x) x.begin()+1,x.end()
#define mset(x,n) memset(x,(n),sizeof(x))
using namespace std;
const long long MOD = (long long) 1e9+7;
template<class X,class Y> bool minimize(X &a,Y b){ if (a>b) {a=b; return true;} return false;}
template<class X,class Y> bool maximize(X &a,Y b){ if (a<b) {a=b; return true;} return false;}
void setup(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
if (fopen(FNAME".inp","r")){
freopen(FNAME".inp","r",stdin);
freopen(FNAME".out","w",stdout);
}
}
int n,D;
vector<int> a;
void init(){
cin>>n>>D;
vector<int> org(n);
for (int &x:org) cin>>x;
vector<int> compress(allof(org));
sort(allof(compress));
compress.resize(unique(allof(compress))-compress.begin());
a.resize(n+1,0);
for (int i=1;i<=n;i++){
int t = lower_bound(allof(compress),org[i-1]) - compress.begin() + 1;
a[i] = t;
}
}
// ! ACed
namespace Bitmask2N{
void solve(){
int MAXMASK = 1<<n;
int res=0;
for (int mask=0;mask<MAXMASK;mask++){
vector<int> indices;
for (int i=0;i<n;i++){
if (mask & (1<<i)){
indices.push_back(i);
}
}
vector<int> val;
bool check=1;
sort(allof(indices));
for (int i=1;i<(int)indices.size();i++){
if (abs(indices[i] - indices[i-1])>D){
check=0;
break;
}
}
if (!check) continue;
for (int x:indices){
val.push_back(a[x+1]);
}
int score = 0, curmax = -1;
for (int v : val) {
if (v > curmax) {
score++;
curmax = v;
}
}
maximize(res, score);
}
cout<<res;
exit(0);
}
};
// ! ACed
namespace DPN3{
void solve(){
int m = *max_element(allof(a));
// ! dp[pos][cur]: maximum impression score if ending at pos and max is cur
int dp[n+1][m+1];
mset(dp,-0x3f3f3f);
for (int i=1;i<=n;i++){
dp[i][a[i]]=1;
}
for (int i=1;i<=n;i++){
for (int cur=0;cur<=m;cur++){
if (dp[i][cur]==-1) continue;
for (int nxt=i+1;nxt<=n and nxt-i <=D;nxt++){
maximize(dp[nxt][max(cur,a[nxt])],dp[i][cur] + (a[nxt] > cur));
}
}
}
int res=0;
for (int cur=0;cur<=m;cur++) maximize(res,dp[n][cur]);
cout<<res;
exit(0);
}
};
// ! ACed
namespace NormalLIS{
void solve(){
vector<int> dp;
vector<int> fordp(allof1(a));
for (int x:fordp){
vector<int>::iterator it = lower_bound(allof(dp),x);
if (it == dp.end()) dp.push_back(x);
else *it = x;
}
cout<<dp.size();
exit(0);
}
};
namespace Finale{
struct SegmentTree{
int n;
vector<int> st;
SegmentTree(int N=0){
n=N;
if (n>0){
st.assign(4*n+1,0);
}
}
void update(int node,int l,int r,int pos,int val){
if (l==r){
st[node] = val;
return;
}
int mid = (l+r)>>1;
if (pos<=mid) update(2*node,l,mid,pos,val);
else update(2*node+1,mid+1,r,pos,val);
st[node] = max(st[2*node],st[2*node+1]);
}
void update(int pos,int val){
update(1,1,n,pos,val);
}
int getMax(int node,int l,int r,int wanted_l,int wanted_r){
if (wanted_r<l or r<wanted_l) return 0;
if (wanted_l<=l and r<=wanted_r) return st[node];
int mid = (l+r)>>1;
return max(getMax(2*node,l,mid,wanted_l,wanted_r),
getMax(2*node+1,mid+1,r,wanted_l,wanted_r));
}
int getMax(int l,int r){
if (l>r) return 0;
return getMax(1,1,n,l,r);
}
};
void solve(){
vector<int> perm(n,0);
iota(allof(perm),1);
sort(allof(perm),[](const int x,const int y){
if (a[x]==a[y]) return x>y;
return a[x] < a[y];
});
set<int> processed;
processed.insert(0);
processed.insert(n+1);
set<int> barrier;
for (int i=1;i<=n-D;i++){
barrier.insert(i);
}
SegmentTree st(n);
for (int x: perm){
set<int>::iterator it = processed.lower_bound(x);
int prer = *it, prel = *(--it);
if (prer-prel>D){
if (prer-x<=D) for (int i=x;i<=prer;i++) barrier.erase(i);
if (x-prel<=D) for (int i=prel;i<=x;i++) barrier.erase(i);
}
processed.insert(x);
it = barrier.lower_bound(x);
int left = (it==barrier.begin() ? 1 : *(--it));
st.update(x,st.getMax(left,x-1)+1);
}
cout<<st.getMax(1,n);
exit(0);
}
}
void sol(){
if (n<=20) Bitmask2N::solve();
if (n<=400) DPN3::solve();
if (D==n) NormalLIS::solve();
Finale::solve();
}
int main(){
setup();
init();
sol();
}
