#include <bits/stdc++.h>
#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())
using namespace std;
template<typename U, typename V> bool maxi(U &a, V b) {
if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
if (a > b) { a = b; return 1; } return 0;
}
const int N = (int)3e5 + 9;
const int mod = (int)1e9 + 7;
void prepare(); void main_code();
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
const bool MULTITEST = 0; prepare();
int num_test = 1; if (MULTITEST) cin >> num_test;
while (num_test--) { main_code(); }
}
void prepare() {};
int a[N];
int b[N], dp[N];
bool on[N];
void main_code() {
int n, d; cin >> n >> d;
for(int i = 1; i <= n; ++i) cin >> a[i];
vector<ii> px;
FOR(i, 1, n) px.push_back(_mp(a[i], i));
sort(px.begin(), px.end());
for(int i = 0, j = 0; i < sz(px); i = j + 1) {
j = i;
while (j + 1 < sz(px) and px[j + 1].fi == px[i].fi) ++j;
FOR(k, i, j) {
int x = px[k].second;
b[x] = 1;
FOD(l, x - 1, max(x - d, 1)) {
b[x] = max(b[x], dp[l] + 1);
}
on[x] = 1;
}
FOR(k, i, j) {
int x = px[k].second;
dp[x] = max(dp[x], b[x]);
for(int i = x + 1, l = x; i <= n; ++i) {
if (on[i]) {
if (i - l > d) break ;
l = i;
dp[i] = max(dp[i], dp[x]);
}
if (a[i] == a[x]) break ;
}
}
}
cout << *max_element(dp + 1, dp + n + 1);
}
/* Let the river flows naturally */
