//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include<bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define all(x) x.begin(), x.end()
const int mod = 1e9 + 7;
const int N = 500001;
using namespace std;
ll n, m, t[N * 4],used[N];
pair <ll, ll> p[N];
vector <ll> v;
struct node{
ll l,r,sum,x;
}mx[N*4];
node mrg (node a, node b){
node c;
c.sum = a.sum + b.sum;
c.l = max (a.l, a.sum + b.l);
c.r = max (b.r, b.sum + a.r);
c.x = max ({a.x,b.x,a.r+b.l});
return c;
}
void UPD (ll idx, ll val, ll tl = 1, ll tr = n, ll v = 1){
if (tl == tr){
mx[v] = {1,1,1,1};
return;
}
ll tm = (tl + tr) / 2;
if (tm < idx){
UPD (idx, val, tm + 1, tr, v + v + 1);
}
else{
UPD (idx, val, tl, tm, v + v);
}
mx[v] = mrg (mx[v + v], mx[v + v + 1]);
}
node GET (ll l, ll r, ll tl = 1, ll tr = n, ll v = 1){
if (tr < l || tl > r){
return {0,0,0,0};
}
if (l <= tl && tr <= r){
return mx[v];
}
ll tm = (tl + tr) / 2;
return mrg (GET (l, r, tl, tm, v + v), GET (l, r, tm + 1, tr, v + v + 1));
}
void upd (ll idx, ll val, ll tl = 1, ll tr = n, ll v = 1){
if (tl == tr){
t[v] = val;
return;
}
ll tm = (tl + tr) / 2;
if (tm < idx){
upd (idx, val, tm + 1, tr, v + v + 1);
}
else{
upd (idx, val, tl, tm, v + v);
}
t[v] = max (t[v + v], t[v + v + 1]);
}
ll get (ll l, ll r, ll tl = 1, ll tr = n, ll v = 1){
if (tr < l || tl > r){
return 0;
}
if (l <= tl && tr <= r){
return t[v];
}
ll tm = (tl + tr) / 2;
return max (get (l, r, tl, tm, v + v), get (l, r, tm + 1, tr, v + v + 1));
}
signed main (){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> m;
for (int i = 1; i <= n; i++){
cin >> p[i].F;
p[i].S = i;
UPD (i, 1);
}
sort (p + 1, p + n + 1);
p[n + 1].F = -1;
ll a = 0;
for (int i = 1; i <= n + 1; i++){
if (p[i].F != p[i - 1].F){
sort (all (v));
reverse (all (v));
for (auto j: v){
ll l = 1, r = j - 1, res = max (1ll, j - m);
while (l <= r){
ll md = (l + r) / 2;
if (GET (md, j - 1).x >= m){
l = md + 1;
}
else{
res = md;
r = md - 1;
}
}
a = get (res, j);
// cout << j << ' ' << p[i].F << ' ' << res << ' ' << a << '\n';
upd (j, a + 1);
UPD (j, 0);
}
v.clear();
}
v.pb (p[i].S);
}
cout << t[1];
}
