#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mxN = 3e5 + 7;
const int SZ = exp2(ceil(log2(mxN)));
const int INF = 1e9 + 7;
int n, d, arr[mxN], seg[4*mxN], dp[mxN], dsu[mxN], lb[mxN];
bool done[mxN];
set<int> inds;
vector<int> pos[mxN];
int find(int x) {
return dsu[x] < 0 ? x : dsu[x] = find(dsu[x]);
}
void unite(int x, int y) {
x = find(x), y = find(y);
if (x == y) return;
if (dsu[x] > dsu[y]) {
swap(x, y);
}
dsu[x] += dsu[y];
dsu[y] = x;
inds.erase(lb[x]);
inds.erase(lb[y]);
lb[x] = min(lb[x], lb[y]);
if (-dsu[x] >= d) {
inds.insert(lb[x]);
}
}
void update(int ind, int val) {
seg[ind+=SZ] = val;
while (ind /= 2) {
seg[ind] = max(seg[2*ind], seg[2*ind+1]);
}
}
int query(int lo, int hi, int ind = 1, int l = 0, int r = SZ - 1) {
if (lo > r || l > hi) {
return -INF;
}
if (lo <= l && r <= hi) {
return seg[ind];
}
int mid = (l+r)/2;
return max(query(lo,hi,2*ind,l,mid), query(lo,hi,2*ind+1,mid+1,r));
}
int32_t main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> d;
vector<int> vec;
for (int i = 0; i < n; ++i) {
cin >> arr[i];
vec.push_back(arr[i]);
}
sort(vec.begin(), vec.end());
int val = 1;
map<int,int> conv;
for (int i = 0; i < n; ++i) {
if (conv.find(vec[i]) == conv.end()) {
conv[vec[i]] = val++;
}
}
vec.clear();
for (int i = 0; i < n; ++i) {
arr[i] = conv[arr[i]];
if (pos[arr[i]].empty()) {
vec.push_back(arr[i]);
}
pos[arr[i]].push_back(i);
lb[i] = i;
if (i < n-1) {
update(i, -INF);
}
}
sort(vec.begin(), vec.end());
inds.insert(n);
memset(dsu, -1, sizeof(dsu));
for (int i = vec.size()-1; i >= 0; --i) {
for (auto x : pos[vec[i]]) {
int to = *inds.upper_bound(x);
dp[x] = query(x, min(n-1, to+d-1)) + 1;
}
for (auto x : pos[vec[i]]) {
update(x, dp[x]);
done[x] = true;
if (d == 1) {
inds.insert(x);
}
if (done[x+1]) {
unite(x,x+1);
}
if (x && done[x-1]) {
unite(x,x-1);
}
}
}
/*
for (int i = 0; i < n; ++i) {
cout << query(i,i) << ' ';
}
cout << "\n";
*/
cout << query(0, n-1) << "\n";
}
