#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define eb emplace_back
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
const int N = 3e5 + 5, MAXN = 1e7 + 5;
const long long oo = 1e9 + 7, mod = 1e9 + 7;
int n, d;
ii a[N];
int IT[N << 2], dp[N];
set<ii> se;// segments with length >= d
bool out[N];
void upd(int id, int l, int r, int pos, int vl){
if(l == r){
IT[id] = vl;
return;
}
int mid = (l + r) >> 1;
if(pos <= mid) upd(id << 1, l, mid, pos, vl);
else upd(id << 1 | 1, mid + 1, r, pos, vl);
IT[id] = max(IT[id << 1], IT[id << 1 | 1]);
}
int get(int id, int l, int r, int L, int R){
if(l > R || r < L || l > r) return 0;
if(l >= L && r <= R) return IT[id];
int mid = (l + r) >> 1;
return max(get(id << 1, l, mid, L, R), get(id << 1 | 1, mid + 1, r, L, R));
}
bool cmp(ii a, ii b){
if(a.fi != b.fi) return a.fi < b.fi;
else return a.se > b.se;
}
void er(int temp){
out[temp] =1 ;
set<ii>::iterator it = se.lower_bound({temp, oo});
if(it != se.begin()){
//if(temp == 11) cout << temp << "\n";
it--;
ii tmp1 = (*it), tmp2 = {tmp1.fi, temp - 1}, tmp3 = {temp + 1, tmp1.se};
if(tmp1.se < temp || tmp1.fi > temp) return;
//if(temp == 11) cout << tmp1.fi << " " << tmp1.se << " " << temp << "\n";
se.erase(tmp1);
//cout << tmp2.fi << " " << tmp2.se << " " << tmp3.fi << " " << tmp3.se << "\n";
if((tmp2.se - tmp2.fi + 1) >= d){
//if(temp == 11) cout << tmp2.fi << " " << tmp2.se << "\n";
se.insert(tmp2);
}
if((tmp3.se - tmp3.fi + 1) >= d) se.insert(tmp3);
}
}
int saves[N];
void process(){
cin >> n >> d;
for(int i = 1; i <= n; i++){
cin >> a[i].fi;
a[i].se = i;
}
sort(a + 1, a + n + 1, cmp);
se.insert({1, n});
int ans = -1, itr = 1;
for(int i = 1; i <= n; i++){
//if(se.find({1, 11}) != se.end()) cout << i << "\n";
int temp = a[i].se;
//if(temp == 12) cout << out[11] << "\n";
while(itr <= n && a[itr].fi == a[i].fi){
er(a[itr].se);
itr++;
}
//cout << i << " " << itr << "\n";
//cout << i << "\n";
//for(auto it : se) cout << it.fi << " " << it.se << "\n";
int lst = 1;
set<ii>::iterator it = se.lower_bound({temp, oo});
if(it != se.begin()){
it--;
//if(temp == 12) cout << (*it).fi << " " << (*it).se << "\n";
lst = (*it).se + 1;
}
saves[temp] = lst;
//cout << i << " " << temp << " " << lst << "\n";
dp[temp] = get(1, 1, n, lst, temp - 1) + 1;
//cout << dp[temp] << "\n";
upd(1, 1, n, temp, dp[temp]);
ans = max(ans, dp[temp]);
}
//for(int i = 1; i <= n; i++) cout << i << " " << saves[i] << "\n";
cout << ans;
}
signed main(){
ios_base::sync_with_stdio(0);
#ifdef nqm
freopen("input.inp", "r", stdin);
freopen("output.out", "w", stdout);
#endif
#ifndef nqm
#endif
process();
}
