#include <bits/stdc++.h>
#define dbg(x) cout << #x <<' '<< x << endl;
#define mod 1000000007LL
#define inf 1e17
#define ll long long
using namespace std;
void printvec(vector<ll> vec) {
for (auto &&e : vec) {
cout << e << ' ';
}
cout << endl;
}
ll maxn = 300000+5;
vector<ll> tree(4*maxn, inf);
ll query(ll l, ll r, ll x, ll y, ll node)
{
if(max(l, x) > min(r, y))
{
return inf;
}
if(x <= l && r <= y)
{
return tree[node];
}
ll mid = (l+r)/2;
return min(query(l, mid, x,y, node*2+1), query(mid+1, r, x, y, node*2+2));
}
void update(ll l, ll r, ll pos, ll val, ll node)
{
if(pos > r || pos < l) return;
if(l==r)
{
tree[node] = val;
return;
}
ll mid = (l+r)/2;
update(l, mid, pos, val, node*2+1);
update(mid+1, r, pos, val, node*2+2);
tree[node] = min(tree[node*2+1], tree[node*2+2]);
}
vector<ll> tree2(maxn*4);
ll query2(ll l, ll r, ll x, ll y, ll node)
{
if(max(l, x) > min(r, y))
{
return 0;
}
if(x <= l && r <= y)
{
return tree2[node];
}
ll mid = (l+r)/2;
return max(query2(l, mid, x,y, node*2+1), query2(mid+1, r, x, y, node*2+2));
}
void update2(ll l, ll r, ll pos, ll val, ll node)
{
if(pos > r || pos < l) return;
if(l==r)
{
tree2[node] = val;
return;
}
ll mid = (l+r)/2;
update2(l, mid, pos, val, node*2+1);
update2(mid+1, r, pos, val, node*2+2);
tree2[node] = max(tree2[node*2+1], tree2[node*2+2]);
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
ll n, d;
cin >> n >> d;
vector<ll> a(n);
for (int i = 0; i < n; i++) cin >> a[i];
vector<ll> temp = a;
sort(temp.begin(),temp.end());
vector<ll> order(n);
map<ll,ll> rnk;
ll cur=0;
for (int i = 0; i < n;i++)
{
if(i == 0 || temp[i]!=temp[i-1])
{
cur++;
}
rnk[temp[i]] = cur;
}
for (int i = 0; i < n; i++)
{
order[i] = rnk[a[i]];
}
ll l, r;
l=r=0;
deque<pair<ll,ll>> dq;
for (int i = 0; i < d; i++)
{
while(!dq.empty() && dq.back().first >= order[i])
{
dq.pop_back();
}
dq.push_back({order[r], r});
r++;
}
map<ll,ll> minsi;
minsi[r-1] = dq[0].first;
while(r<n)
{
while(!dq.empty() && dq.back().first >= order[r])
{
dq.pop_back();
}
dq.push_back({order[r], r});
r++;
if(l == dq[0].second) dq.pop_front();
l++;
minsi[r-1] = dq[0].first;
}
vector<ll> R(n);
for (int i=n-1;i>=0;i--)
{
R[i] = query(1, n, order[i]+1, n, 0);
if(R[i] == inf) R[i] = n-1;
if(minsi[i] != 0)
{
update(1, n, minsi[i], i,0);
}
}
vector<ll> dp(n,1);
vector<pair<ll,ll>> v(n);
for (int i=0;i<n;i++)
{
v[i] = {order[i],i};
}
sort(v.begin(), v.end(), [](pair<ll,ll> p1, pair<ll,ll> p2){if(p1.first == p2.first) return p1.second < p2.second; else return p1.first > p2.first;});
for (int i = 0; i < n; i++)
{
dp[v[i].second] += query2(0,n-1,v[i].second,R[v[i].second],0);
update2(0,n-1,v[i].second,dp[v[i].second],0);
}
cout << *max_element(dp.begin(), dp.end()) << endl;
}
