#undef _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define int long long
#define pb push_back
#define fi first
#define si second
#define ar array
typedef pair<int,int> pi;
typedef tuple<int,int,int> ti;
void debug_out() {cerr<<endl;}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {cerr<<" "<<to_string(H);debug_out(T...);}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:",debug_out(__VA_ARGS__)
int N, D;
int dp[300010], cnt[300010], ans;
vector<int> A, old;
struct node {
node *l, *r;
int val, s, m, e, lazy, upd;
node(int _s, int _e) {
s = _s, e = _e;
m = (s + e) / 2;
val = 0; lazy = 0; upd = false;
if (s != e) {
l = new node(s, m);
r = new node(m+1, e);
}
}
void pushdown() {
if (upd) {
val = lazy;
if (s != e) {
l->lazy = lazy;
r->lazy = lazy;
}
upd = false;
}
}
void set(int qs, int qe, int v) {
if (qs == s && qe == e) {lazy = v; upd = true;}
else {
if (qs > m) r->set(qs, qe, v);
else if (qe <= m) l->set(qs, qe, v);
else l->set(qs, m, v), r->set(m + 1, qe, v);
l->pushdown(), r->pushdown();
val = max(l->val, r->val);
}
}
int get(int qs, int qe) {
pushdown();
if (qs <= s && qe >= e) return val;
if (qs > m) return r->get(qs, qe);
if (qe <= m) return l->get(qs, qe);
return max(l->get(qs, m), r->get(m + 1, qe));
}
} *seg;
vector<int> discretize(vector<int> V) {
vector<int> dis = V;
sort(dis.begin() + 1,dis.end());
dis.resize(unique(dis.begin() + 1,dis.end())-dis.begin());
for (int i = 0; i < (int)V.size(); i++) {
V[i + 1] = lower_bound(dis.begin() + 1,dis.end(), V[i + 1])-dis.begin();
}
return V;
}
signed main() {
fast;
cin >> N >> D;
A.resize(N + 1);
for (int i = 1; i <= N; ++i) cin >> A[i];
old = A;
A = discretize(A);
seg = new node(1, N);
dp[1] = 1;
seg->set(A[1], A[1], 1);
cnt[A[1]] = 1;
int lx = 1;
for (int i = 2; i <= N; ++i) {
++cnt[A[i]];
while (lx < N && i - lx > D) {
--cnt[A[lx]];
if (cnt[A[lx]] == 0) seg->set(A[lx], A[lx], 0);
++lx;
}
if (A[i] > 1) dp[i] = seg->get(1, A[i] - 1) + 1;
else dp[i] = 1;
// debug(i);
// for (int j = 1; j <= N; ++j) cout << seg->get(j, j) << ' ';
// cout<<endl;
if (dp[i] > seg->get(A[i], A[i])) seg->set(A[i], A[i], dp[i]);
ans = max(ans, dp[i]);
}
cout << ans;
return 0;
}
