#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define mk make_pair
#define endl '\n'
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int N = 2050;
int n, d, a[N], b[N];
int dp[N][N], pmx[N][N];
void solve() {
cin >> n >> d;
for (int i = 1; i <= n; i++) {
cin >> a[i];
b[i] = a[i];
}
sort(b+1, b+n+1);
int m = unique(b+1, b+n+1)-b-1;
for (int i = 1; i <= n; i++) {
a[i] = lower_bound(b+1, b+m+1, a[i])-b;
}
for (int i = 1; i <= n; i++) {
for (int x = a[i]; x <= m; x++) {
dp[i][x] = 1;
for (int j = i-d; j <= i-1; j++) {
dp[i][x] = max(dp[i][x], pmx[j][x]);
if (x == a[i]) dp[i][x] = max(dp[i][x], pmx[j][x-1] +1);
}
pmx[i][x] = max(pmx[i][x-1], dp[i][x]);
}
}
cout << pmx[n][m] << endl;
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
