#ifndef SorahISA
#define SorahISA
#include SorahISA __FILE__ SorahISA
struct SegTree {
vector<int> seg;
int maxn;
void init(int N) {
maxn = (1 << (__lg(N+1) + 1));
seg.assign(maxn<<1, 0);
}
void pull(int now) {
int lt = now << 1, rt = lt | 1;
seg[now] = max(seg[lt], seg[rt]);
}
void modify_point_chmax(int qX, int val) {
// debug(qX, val);
chmax(seg[qX += maxn], val);
while ((qX >>= 1)) pull(qX);
}
int query_range_max(int qL, int qR) {
// debug(qL, qR);
int ans = max(seg[qL += maxn], seg[qR += maxn]);
while (qL + 1 < qR) {
if (~qL & 1) chmax(ans, seg[qL ^ 1]);
if ( qR & 1) chmax(ans, seg[qR ^ 1]);
qL >>= 1, qR >>= 1;
}
return ans;
}
};
void solve() {
int N, D; cin >> N >> D;
vector<int> A(N);
map<int, vector<int>> mp;
for (int i = 0; i < N; ++i) cin >> A[i], mp[A[i]].eb(i);
sort(RALL(A)), A.erase(unique(ALL(A)), end(A));
set<pii> st_all, st_large;
auto print_set = [&](const set<pii> &st) {
cerr << "\u001b[36m";
cerr << "{";
for (const auto &p : st) cerr << p << ", ";
cerr << "}\n";
cerr << "\u001b[0m";
};
auto check_large = [&](int x) -> bool {
auto it = st_large.upper_bound({x, x});
if (it != begin(st_large)) it = prev(it);
if (it == end(st_large)) return false;
return (it->first <= x and x <= it->second);
};
auto insert_point = [&](int x) {
/// x is not in st_all ///
auto it = st_all.ee(x, x).first;
int l = x, r = x;
/// if x+1 is in st_all, merge them ///
if (next(it) != end(st_all) and next(it)->first == x+1) {
r = next(it)->second;
/// remove x+1 from st_large if exist ///
if (check_large(r)) st_large.erase(*next(it));
it = st_all.erase(it); /// remove [x, x]
it = st_all.erase(it); /// remove [x+1, r]
it = st_all.ee(l, r).first; /// insert [x, r]
}
/// if x-1 is in st_all, merge them ///
if (it != begin(st_all) and prev(it)->second == x-1) {
l = prev(it)->first;
/// remove x-1 from st_large if exist ///
if (check_large(l)) st_large.erase(*prev(it));
it = st_all.erase(it); /// remove [x, r]
it = st_all.erase(prev(it)); /// remove [l, x-1]
it = st_all.ee(l, r).first; /// insert [l, r]
}
/// insert [l, r] into st_large if large enough ///
if (r - l + 1 >= D) st_large.ee(l, r);
// print_set(st_all);
// print_set(st_large);
};
auto query_stop = [&](int x) -> int {
/// x is not in st_large ///
auto it = st_large.upper_bound({x, x});
return (it != end(st_large) ? it->first + D - 1 : N - 1);
};
SegTree seg; seg.init(N);
for (int val : A) {
// debug(val);
vector<int> L, R;
for (int pos : mp[val]) {
// debug(pos);
L.eb(pos), R.eb(query_stop(pos)), insert_point(pos);
seg.modify_point_chmax(pos, seg.query_range_max(L.back(), R.back()) + 1);
}
for (int i = SZ(L)-1; i >= 0; --i) {
seg.modify_point_chmax(L[i], seg.query_range_max(L[i], R[i]));
}
// for (int i = 0; i < SZ(L); ++i) {
// int dp = seg.query_range_max(L[i], L[i]);
// debug("dp", L[i], dp);
// }
}
cout << seg.query_range_max(0, N-1) << "\n";
// vector<int> dp(N, 1);
// for (int i = N-1; i >= 0; --i) {
// for (int j = i+1, cnt = 1; cnt <= D and j < N; ++j, ++cnt) {
// if (A[j] > A[i]) chmax(dp[i], dp[j] + 1);
// else if (A[j] == A[i]) chmax(dp[i], dp[j]), cnt = 0;
// else if (A[j] < A[i]) cnt = 0;
// }
// // debug(i, A[i], dp[i]);
// }
// cout << *max_element(ALL(dp)) << "\n";
}
int32_t main() {
fastIO();
int t = 1; // cin >> t;
for (int _ = 1; _ <= t; ++_) {
solve();
}
return 0;
}
#else
#ifdef local
#define _GLIBCXX_DEBUG 1
#endif
#pragma GCC optimize("Ofast", "unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using int64 = long long;
#define int int64
using float80 = long double;
#define double float80
using pii = pair<int, int>;
template <typename T> using Prior = std::priority_queue<T>;
template <typename T> using prior = std::priority_queue<T, vector<T>, greater<T>>;
#define eb emplace_back
#define ef emplace_front
#define ee emplace
#define pb pop_back
#define pf pop_front
#define ALL(x) begin(x), end(x)
#define RALL(x) rbegin(x), rend(x)
#define SZ(x) ((int)(x).size())
ostream & operator << (ostream &os, const pii &p) {
return os << "(" << p.first << ", " << p.second << ")";
}
#ifdef local
#define fastIO() void()
#define debug(...) \
fprintf(stderr, "\u001b[33m"), \
fprintf(stderr, "At [%s], line %d: (%s) = ", __FUNCTION__, __LINE__, #__VA_ARGS__), \
_do(__VA_ARGS__), \
fprintf(stderr, "\u001b[0m")
template <typename T> void _do(T &&_t) { cerr << _t << "\n"; }
template <typename T, typename ...U> void _do(T &&_t, U &&..._u) { cerr << _t << ", ", _do(_u...); }
#else
#define fastIO() ios_base::sync_with_stdio(0), cin.tie(0)
#define debug(...) void()
#endif
template <typename T, typename U> bool chmin(T &lhs, U rhs) { return lhs > rhs ? lhs = rhs, 1 : 0; }
template <typename T, typename U> bool chmax(T &lhs, U rhs) { return lhs < rhs ? lhs = rhs, 1 : 0; }
#endif
