// #pragma GCC optimize ("Ofast")
// #pragma GCC target ("avx2")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#else
#define debug(...)
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
// #define int long long
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
#define FOR(i, l, r) for (int i = (l); i <= (r); ++i)
#define FOS(i, r, l) for (int i = (r); i >= (l); --i)
#define FRN(i, n) for (int i = 0; i < (n); ++i)
#define FSN(i, n) for (int i = (n) - 1; i >= 0; --i)
#define EACH(i, x) for (auto &i : (x))
#define WHILE while
template<typename T> T gcd(T a, T b) { T d2 = (a | b) & -(a | b); a /= d2; b /= d2; WHILE(b) { a = a % b; swap(a, b); } return a * d2; }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
void _assert(bool statement) { if (statement) return; cerr << "\n>> Assertion failed!\n"; exit(0); }
void _assert(bool statement, const str &message) { if (statement) return; cerr << "\n>> Assertion failed: " << message << '\n'; exit(0); }
void _error(const str &message) { cerr << "\n>> Error: " << message << '\n'; exit(0); }
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
END OF TEMPLATE
----------------------------------------------------------------
Tran The Bao - ghostwriter
Training for VOI23 gold medal
----------------------------------------------------------------
GOAT
----------------------------------------------------------------
*/
const int oo = 1e9 + 5;
const int N = 3e5 + 5;
const int T = 12e6 + 5;
int n, d, l[N], d1[N], tr[T];
pi a[N];
multiset<pi> s, s1;
void reinit(int test_id) {
}
void input(int test_id) {
cin >> n >> d;
FOR(i, 1, n) {
cin >> a[i].st;
a[i].nd = i;
}
}
void upd(int i, int l, int r, int q, int v) {
if (r < q || l > q) return;
if (l == r) {
tr[i] = v;
return;
}
int mid = l + (r - l) / 2;
upd(i * 2, l, mid, q, v);
upd(i * 2 + 1, mid + 1, r, q, v);
tr[i] = max(tr[i * 2], tr[i * 2 + 1]);
}
void upd(int pos, int v) { upd(1, 1, n, pos, v); }
int get(int i, int l, int r, int ql, int qr) {
if (r < ql || l > qr) return 0;
if (ql <= l && r <= qr) return tr[i];
int mid = l + (r - l) / 2;
return max(get(i * 2, l, mid, ql, qr), get(i * 2 + 1, mid + 1, r, ql, qr));
}
int get(int ql, int qr) { return get(1, 1, n, ql, qr); }
bool valid(pi x) { return abs(x.st) != oo; }
void del(int i) {
auto cur = *--s.ub({i, oo});
s.ers(cur);
if (cur.nd - cur.st + 1 >= d) s1.ers(cur);
if (cur.st < i) {
s.ins({cur.st, i - 1});
if (i - cur.st >= d) s1.ins({cur.st, i - 1});
}
if (i < cur.nd) {
s.ins({i + 1, cur.nd});
if (cur.nd - i >= d) s1.ins({i + 1, cur.nd});
}
}
int find(int i) {
if (!i) return i + 1;
auto cur = *--s1.ub({i, oo});
if (!valid(cur)) return 1;
if (cur.nd <= i) return cur.nd - d + 1;
if (i - cur.st + 1 >= d) return i - d + 1;
cur = *----s1.ub({i, oo});
if (!valid(cur)) return 1;
return cur.nd - d + 1;
}
void solve(int test_id) {
s.ins({-oo, -oo});
s.ins({oo, oo});
s.ins({1, n});
s1.ins({-oo, -oo});
s1.ins({oo, oo});
s1.ins({1, n});
sort(a + 1, a + 1 + n);
FOR(i, 1, n) {
int j = i;
WHILE(j <= n && a[j].st == a[i].st) ++j;
--j;
FOR(z, i, j) {
l[a[z].nd] = find(a[z].nd - 1);
d1[a[z].nd] = get(l[a[z].nd], a[z].nd) + 1;
}
FOR(z, i, j) {
del(a[z].nd);
upd(a[z].nd, d1[a[z].nd]);
}
i = j;
}
int rs = 0;
FOR(i, 1, n) rs = max(rs, d1[i]);
cout << rs;
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
int test_num = 1;
// cin >> test_num; // comment if the problem does not requires multitest
FOR(i, 1, test_num) {
input(i); // input in noninteractive sections for case #i
solve(i); // main function to solve case #i
reinit(i); // reinit global data to default used in case #i
}
#ifdef LOCAL
cerr << "\nTime: " << setprecision(5) << fixed << (ldb)clock() / CLOCKS_PER_SEC << "ms.\n";
#endif
return 0;
}
/*
11 2
1 4 4 2 2 4 9 5 7 0 3
----------------------------------------------------------------
From Benq:
stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/
