#include <bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define FOD(i, a, b) for(int i = a; i >= b; i--)
#define fi first
#define se second
#define ll long long
#define db double
#define ii pair<int,int>
#define pb push_back
#define MASK(i) (1LL << i)
#define sq(i) (1LL * (i) * (i))
#define task "task"
const ll INF = 1e18;
const int inf = 1e9;
const int N = 3e5 + 4;
int n, d, nv;
int a[N];
vector<int> val;
queue<ii> q[N];
void opti(ii &a, ii b) {
if(a.fi < b.fi || (a.fi == b.fi && a.se > b.se)) a = b;
}
struct Smt {
int mx[4 * N];
void init() {
FOR(i, 1, 4 * nv) mx[i] = -1;
}
void upd(int id, int l, int r, int pos, int d) {
if(pos < l || pos > r) return;
if(l == r) {
mx[id] = d;
return;
}
int mid = l + r >> 1;
upd(id << 1, l, mid, pos, d);
upd(id << 1 | 1, mid + 1, r, pos, d);
mx[id] = max(mx[id << 1], mx[id << 1 | 1]);
}
ii get(int id, int l, int r, int u, int v) {
if(l > v || r < u) return {-1, inf};
if(l >= u && r <= v) return {mx[id], l};
int mid = l + r >> 1;
ii n1 = get(id << 1, l, mid, u, v);
ii n2 = get(id << 1 | 1, mid + 1, r, u, v);
opti(n1, n2);
return n1;
}
} smt;
signed main() {
if(fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> d;
FOR(i, 1, n) {
cin >> a[i];
val.pb(a[i]);
}
val.pb(-1);
sort(val.begin(), val.end());
val.erase(unique(val.begin(), val.end()), val.end());
nv = val.size();
FOR(i, 1, n) a[i] = lower_bound(val.begin(), val.end(), a[i]) - val.begin() + 1;
smt.init();
int res = 0;
FOR(i, 1, n) {
ii tmp = smt.get(1, 1, nv, 1, a[i] - 1);
ii best = {1, a[i]};
if(tmp.fi != -1) opti(best, {tmp.fi + 1, a[i]});
tmp = smt.get(1, 1, nv, a[i], nv);
if(tmp.fi != -1) opti(best, tmp);
// cout << i << ' ' << best.fi << ' ' << best.se << '\n';
while(q[best.se].size() && q[best.se].front().fi <= best.fi) q[best.se].pop();
q[best.se].push({best.fi, i});
smt.upd(1, 1, nv, best.se, q[best.se].front().fi);
if(i - d > 0) {
while(q[a[i - d]].size() && q[a[i - d]].front().se <= i - d) q[a[i - d]].pop();
}
if(q[a[i - d]].size()) smt.upd(1, 1, nv, a[i - d], q[a[i - d]].front().fi);
else smt.upd(1, 1, nv, a[i - d], -1);
if(i == n) cout << best.fi << '\n';
}
}
