#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <typename T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#define endl '\n'
#define ll long long
#define pb push_back
#define vi vector<int>
#define vll vector<long long>
#define sz(x) (int)x.size()
#define int long long
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define piii pair<int,pii>
#define rep(i,a,b) for (ll i = a; i<b; i++)
#define repo(i,a,b) for (int i = a; i>=b; i--)
#define sets(a,b) memset(a, b, sizeof(a))
#define fi first
#define se second
int dy[8] = {0, 0, 1, -1, 1, -1 , 1, -1};
int dx[8] = {1, -1, 0, 0, 1, -1, -1, 1};
//int dp[100001][100001];
//int arr[100001];
const int MOD = 1e9+7;
const int INF = 1e9;
const int LOG = 20;
const int maxn = 1e5 + 5;
void solve(){
int n,d;
cin>>n>>d;
vi v(n+1);
for(int i=0;i<n;i++){
cin>>v[i];
}
//subtask 1 bitmasks
vector<vi> ans;
for(int i =0;i<=(1<<n);i++){
int temp = i;
vi t;
bool flag = true;
int cnt = 0;
while(temp>0){
if(temp&1){
t.pb(cnt);
}
cnt++;
temp = (temp>>1);
}
for(int j = 0;j<sz(t)-1;j++){
if(abs(t[j]-t[j+1])>d){
flag = false;
break;
}
}
if(flag){
for(int j = 0;j<sz(t);j++){
t[j] = v[t[j]];
}
ans.pb(t);
}
}
int sol = -1;
for(auto x : ans){
int cnt = 0;
int curmax = -1;
for(int i = 0;i<sz(x);i++){
if(x[i]>curmax){
cnt++;
curmax = x[i];
}
}
sol = max(sol,cnt);
}
cout<<sol<<endl;
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int k = 1;
while(k--){
solve();
}
return 0;
}
