#include<iostream>
#include<algorithm>
#include<vector>
#include<utility>
#define ln (e-s+1)
#define md ((e+s)/2)
#define dm ((e+s)/2 + 1)
#define lc (id*2)
#define rc (id*2 + 1)
#define ll long long
#define F first
#define S second
#define pll pair<ll , ll>
#define pii pair<int, int>
#define pb push_back
using namespace std;
const int N = 7002, inf = (int)1e9 + 7;
int n, d, a[N];
int dp[N][N];
vector<int> vct;
int seg[N][N << 2];
void build(int k,int id = 1,int s = 1,int e = n){
seg[k][id] = -inf;
if(ln > 1)build(k, lc, s, md), build(k, rc, dm ,e);
}
void upd(int k, int p,int x,int id = 1,int s = 1,int e = n){
if(p < s || p > e)return;
if(ln == 1){
seg[k][id] = max(seg[k][id], x);
return;
}upd(k , p, x, lc, s, md), upd(k, p, x, rc, dm, e);
seg[k][id] = max(seg[k][lc], seg[k][rc]);
}
int get(int k,int l,int r,int id = 1,int s = 1,int e = n){
if(r < s|| l > e)return -inf;
if(l <= s && e <= r)return seg[k][id];
return max(get(k, l, r, lc, s, md), get(k, l, r, rc, dm , e));
}
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> d;
for(int i = 1; i <= n; i ++) cin >> a[i], vct.pb(a[i]);
sort(vct.begin(), vct.end()); unique( vct.begin(), vct.end());
for(int i = 1; i <= n; i ++){
a[i] = (lower_bound(vct.begin(), vct.end(), a[i]) - vct.begin());
}
for(int i = 0; i <= n; i ++)fill(dp[i], dp[i] + N, -inf);
dp[1][a[1]] = 1; upd(a[1], 1, 1);
for(int i = 2; i <= n; i ++){
dp[i][a[i]] = 1; upd(a[i], i, 1);
for(int k = 0 ; k < a[i]; k ++){
dp[i][a[i]] = max(dp[i][a[i]] , get(k, max(1,i-d), i-1) + 1);
upd(a[i], i, dp[i][a[i]]);
}
for(int k = a[i]; k <= n; k ++){
dp[i][k] = max(dp[i][k], get(k , max(1, i - d), i-1));
upd(k, i, dp[i][k]);
}
}
int ret = 0;
for(int i = 0; i <= n; i ++)ret = max(ret, dp[n][i]);
cout << ret << endl;
}
