#include <bits/stdc++.h>
using namespace std;
 
int dp[100000];
int rec(int arr[],int i,int n,int kk){
	if(i==n-1)
	return 0;
	if(i>n-1)
	return INT_MAX;
	if(dp[i]!=-1)
	return dp[i];
 
	// int f=INT_MAX;
	// if(i+1<n)
	// f=rec(arr,i+1,n)+abs(arr[i]-arr[i+1]);
	// int k=INT_MAX;
	// if(i+2<n)
	// k=rec(arr,i+2,n)+abs(arr[i]-arr[i+2]);
	int cost=INT_MAX;
	for(int l=1;l<=kk;l++){
		if(i+l<n)
		cost=min(cost,rec(arr,i+l,n,kk)+abs(arr[i]-arr[i+l]));
	}
 
 
	return dp[i]=cost;
}
int main() {
	memset(dp,-1,sizeof(dp));
	int n,k;
	cin>>n>>k;
	int arr[n];
	for(int i=0;i<n;i++){
		cin>>arr[i];
	}
	cout<<rec(arr,0,n,k)<<endl;
	return 0;
}

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