#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
using namespace std;
const int mxn=3e5+5;
const int inf=1e9;
int n, D;
int a[mxn];
struct segtree {
int tree[4 * mxn] = {};
int pref[4 * mxn] = {};
int suf[4 * mxn] = {};
void build(int node,int b,int e) {
if(b==e) {
tree[node] = 1;
suf[node] = 1;
pref[node] = 1;
return;
}
int mid=b+e>>1;
int left=node<<1;
int right=left|1;
build(left,b,mid);
build(right,mid+1,e);
tree[node] = pref[node] = suf[node] = e - b + 1;
}
void update(int node,int b,int e,int p) {
if(e<p || b>p)return;
if(b == e) {
tree[node] = 0;
suf[node] = 0;
pref[node] = 0;
return;
}
int mid=b+e>>1;
int left=node<<1;
int right=left|1;
update(left,b,mid,p);
update(right,mid+1,e,p);
tree[node] = max({tree[left], tree[right], suf[left] + pref[right]});
suf[node] = suf[right];
pref[node] = pref[left];
if(suf[right] == e - mid) suf[node] += suf[left];
if(pref[left] == mid - b + 1) pref[node] += pref[right];
}
int query(int node, int b, int e, int p) {
if(b > p) return -1;
if(e <= p && suf[node] >= D) {
return e;
}
if(tree[node] < D) return -1;
int mid = b + e >> 1;
int left = node << 1;
int right = left | 1;
if(p <= mid) return query(left, b, mid, p);
int vr = query(right, mid + 1, e, p);
if(vr != -1) return vr;
if(mid + pref[right] <= p && suf[left] + pref[right] >= D) return mid + pref[right];
if(mid + pref[right] > p && p - mid + suf[left] >= D) return p;
return query(left, b, mid, p);
}
} st;
struct sgtree {
int tree[4*mxn] = {};
void update(int node,int b,int e,int p,int v) {
if(e<p || b>p)return;
if(b == e) {
tree[node] = v;
return;
}
int mid=b+e>>1;
int left=node<<1;
int right=left|1;
update(left,b,mid,p,v);
update(right,mid+1,e,p,v);
tree[node]=max(tree[left],tree[right]);
}
int query(int node, int b, int e, int l, int r) {
if(e < l || b > r) return 0;
if(b >= l && e <= r) return tree[node];
int mid=b+e>>1;
int left=node<<1;
int right=left|1;
return max(query(left, b, mid, l, r), query(right, mid + 1, e, l, r));
}
} rmq;
int main() {
cin >> n >> D;
vector<int> v;
vector<int> con[n + 1];
for(int i = 1; i <= n; i++) {
cin >> a[i];
v.push_back(a[i]);
}
sort(v.begin(),v.end());
v.erase(unique(v.begin(), v.end()), v.end());
for(int i = 1; i <= n; i++) {
a[i] = lower_bound(v.begin(), v.end(), a[i]) - v.begin() + 1;
con[a[i]].push_back(i);
}
st.build(1, 1, n);
int dp[n + 1] = {};
int ans = 0;
for(int x = 1; x <= n; x++) {
for(int i : con[x]) {
int p = st.query(1, 1, n, i - 1);
if(p == -1) dp[i] = rmq.query(1, 1, n, 1, i - 1) + 1;
else dp[i] = rmq.query(1, 1, n, p, i - 1) + 1;
}
for(int i : con[x]) {
st.update(1, 1, n, i);
rmq.update(1, 1, n, i, dp[i]);
ans = max(ans, dp[i]);
}
}
cout<<ans<<endl;
}
