#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define fi first
#define si second
typedef pair<int,int> pi;
typedef tuple<int,int,int> ti;
template<typename T> bool chmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
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__)
const int N = 300010;
int n,d;
int a[N],dp[N],ans;
map<int,multiset<pi>> q;
struct node {
node *l, *r;
int val, s, m, e, lazyadd;
node(int _s, int _e): s(_s), e(_e), m((_s+_e)/2), val(0), lazyadd(0), l(NULL), r(NULL) {}
int value() {
if (s == e) return val + lazyadd;
if (lazyadd == 0) return val;
val += lazyadd;
if (l == NULL) l = new node(s, m);
if (r == NULL) r = new node(m+1, e);
l->lazyadd += lazyadd, r->lazyadd += lazyadd;
lazyadd = 0;
return val;
}
void add(int x, int y, int v) {
if (s == x && e == y) lazyadd += v;
else {
if (x > m) {
if (r == NULL) r = new node(m+1, e);
r->add(x, y, v);
}
else if (y <= m) {
if (l == NULL) l = new node(s, m);
l->add(x, y, v);
}
else {
if (r == NULL) r = new node(m+1, e);
if (l == NULL) l = new node(s, m);
l->add(x, m, v), r->add(m+1, y, v);
}
if (l != NULL && r != NULL) val = max(l->value(), r->value());
else if (l == NULL) val = r->value();
else if (r == NULL) val = l->value();
}
}
int query(int x, int y) {
value();
if (s == x && e == y) return value();
if (x > m) return (r==NULL)? 0:r->query(x, y);
if (y <= m) return (l==NULL)? 0:l->query(x, y);
if (l == NULL && r != NULL) return r->query(m+1, y);
if (l != NULL && r == NULL) return l->query(x, m);
if (l != NULL && r != NULL) return max(l->query(x, m),r->query(m+1, y));
return 0;
}
} *st;
void modify(int id, int v) {
st->add(id,id,-st->query(id,id));
st->add(id,id,v);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin.exceptions(ios::badbit|ios::failbit);
cin >> n >> d;
for (int i = 1; i <= n; ++i) cin >> a[i];
st = new node(0,2e9);
for (int i = 1,j=1; i <= n; ++i) {
dp[i]=1;
while (i-j>d) {
while (q[a[j]].size() && q[a[j]].rbegin()->si < i-d) {
q[a[j]].erase(q[a[j]].find(*q[a[j]].rbegin()));
}
if (q[a[j]].size()) modify(a[j],q[a[j]].rbegin()->fi);
else modify(a[j],0);
++j;
}
dp[i]=st->query(0,a[i]-1)+1;
q[a[i]].insert({dp[i],i});
if (dp[i]>st->query(a[i],a[i])) {
modify(a[i],dp[i]);
}
chmax(ans,dp[i]);
}
cout << ans;
return 0;
}
