#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
typedef pair<int,pii>pi2;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
int n,k;
int arr[5005];
int pre[5005];
int suf[5005];
int arr2[5005];
int memo[5005][5005];
int dp(int l, int r){
if(l==r) return 0;
if(memo[l][r]!=-1) return memo[l][r];
int ans=1e15;
int cost=(r>pre[l]);
int cost2=(l<suf[r]);
ans=min(ans,dp(l+1,r)+cost);
ans=min(ans,dp(l,r-1)+cost2);
return memo[l][r]=ans;
}
void solve(){
cin >> n >> k;
vector<int>v;
for(int x=0;x<n;x++){
cin >> arr[x];
v.push_back(arr[x]);
}
sort(v.begin(),v.end());
vector<pii>v2;
for(int x=0;x<n;x++){
int index=lower_bound(v.begin(),v.end(),arr[x])-v.begin();
arr[x]=index/k;
v2.push_back({arr[x],x});
}
sort(v2.begin(),v2.end());
for(int x=0;x<n;x++){
arr2[v2[x].second]=x;
}
vector<int>stk;
for(int x=0;x<n;x++){
while(!stk.empty()&&arr2[stk.back()]<arr2[x]) stk.pop_back();
if(!stk.empty()) pre[arr2[x]]=stk.back();
else pre[arr2[x]]=n+1;
stk.push_back(x);
//cout << pre[x] << " ";
}
//cout << "\n";
stk.clear();
for(int x=n-1;x>=0;x--){
while(!stk.empty()&&arr2[stk.back()]>arr2[x]) stk.pop_back();
if(!stk.empty()) suf[arr2[x]]=stk.back();
else suf[arr2[x]]=0;
stk.push_back(x);
}
memset(memo,-1,sizeof(memo));
cout << dp(0,n-1);
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
//freopen("in.txt","r",stdin);
//freopen("in.txt","w",stdout);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
