/*#pragma GCC optimize("O3")
#pragma GCC optimization("Ofast,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")*/
#include <bits/stdc++.h>
/*#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>*/
#define ll long long
#define ll1 long long
#define ull unsigned long long
#define dou long double
#define str string
#define vll vector<ll>
#define vi vector<int>
#define pll pair<ll, ll>
#define vpll vector<pair<ll, ll>>
#define vbool vector<bool>
#define vstr vector<str>
#define vvll vector<vll>
#define pb push_back
#define pf push_front
#define endl "\n"
#define fr first
#define se second
// #define sortcmp(a) sort(a.begin(), a.end(), cmp)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define speed ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define ordered_set tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>
using namespace std;
//using namespace __gnu_pbds;
const ll INF = 1e18+7;
const int lg = 20;
//const ll MOD = 1e9+7;
const ll MOD2 = 998244353;
mt19937 rng(1488);
ll randll(ll l, ll r) {
return uniform_int_distribution<ll>(l, r)(rng);
}
vll p, s, mn;
ll f(ll v) {
if (p[v] == v) return v;
return p[v] = f(p[v]);
}
void unite(ll a, ll b) {
a = f(a);
b = f(b);
if (a == b) return;
mn[b] = min(mn[b], mn[a]);
mn[a] = min(mn[b], mn[a]);
if (s[a] < s[b]) {
mn[b] = min(mn[b], mn[a]);
p[a] = b;
s[b] += s[a];
}
else {
p[b] = a;
s[a] += s[b];
}
}
vll tree;
ll get(ll l, ll r, ll v, ll tl, ll tr) {
if (l <= tl && tr <= r) return tree[v];
if (tl > r || tr < l) return -INF;
ll tm = (tl+tr)/2;
//push(v, tl, tr);
ll p = get(l, r, v*2, tl, tm), p1 = get(l, r, v*2+1, tm+1, tr);
return max(p,p1);
}
void update(ll idx, ll val, ll v, ll tl, ll tr) {
if (tl == tr) {
tree[v] = val;
return;
}
ll tm = (tl+tr)/2;
//push(v, tl, tr);
if (idx <= tm)update(idx, val, v*2, tl, tm);
else update(idx, val, v*2+1, tm+1, tr);
tree[v] = max(tree[v*2], tree[v*2+1]);
}
int main() {
speed;
ll n, k;
cin >> n >> k;
p.resize(n+7);
s.resize(n+7, 1);
mn.resize(n+7);
vll a(n);
vpll v;
for (int i = 0; i < n; i ++) {
p[i] = mn[i] = i;
cin >> a[i];
v.pb({a[i], i});
}
set<ll> st;
sort(v);
ll k0 = 1;
for (int i = 0; i < n; i ++) {
if (i != 0 && v[i-1].fr != v[i].fr) k0 ++;
a[v[i].se] = k0;
}
reverse(v);
vbool us(n+7, 0);
vll pr(n, -1);
vpll v_;
for (auto i : v) {
if (v_.size() && v_[0].fr != i.fr) {
for (auto j : v_) {
us[j.se] = 1;
if (us[j.se+1]) unite(j.se, j.se+1);
if (j.se > 0 && us[j.se-1]) unite(j.se, j.se-1);
if (s[f(j.se)] >= k) st.insert(mn[f(j.se)]);
}
v_.clear();
}
if (st.lower_bound(i.se) == st.end()) pr[i.se] = n;
else pr[i.se] = *st.lower_bound(i.se)+k-1;
v_.pb(i);
}
tree.resize(k0*4+7, 0);
vll dp(n, 1);
vll c(n+7, -1);
vector<set<ll>> v1(n+7);
/*for (int i = 0; i < n; i ++) {
cout << a[i] << ' ';
}
cout << endl;
for (int i = 0; i < n; i ++) {
cout << pr[i] << ' ';
}
cout << endl;*/
ll maxl = 0;
for (int i = 0; i < n; i ++) {
/*cout << a[i] << endl;
for (int j = 1; j <= k0; j ++) {
cout << get(j, j, 1, 0, k0) << ' ';
}
cout << endl;*/
dp[i] = get(0, a[i]-1, 1, 0, k0)+1;
dp[i] = max(dp[i], get(a[i], a[i], 1, 0, k0));
if (c[a[i]] != -1) {
v1[pr[c[a[i]]]].erase(c[a[i]]);
}
update(a[i], dp[i], 1, 0, k0);
v1[pr[i]].insert(i);
c[a[i]] = i;
for (int j : v1[i]) {
c[a[j]] = -1;
update(a[j], 0, 1, 0, k0);
}
if (pr[i] == n) maxl = max(maxl, dp[i]);
// cout << dp[i] << endl;
}
cout << maxl << endl;
}
