// Original C++ solution (slower):
#define _CRT_SECURE_NO_WARNINGS

/*                   وتزودوا فإن خير الزاد التقوى                    */

/*       وما تدري نفس ماذا تکسب غدا وما تدري نفس باي ارض تموت      */

#include <bits/stdc++.h>

#include<unordered_map>

#include<iomanip>

#include<fstream>

using namespace std;

#include<iostream>

#define endl '\n'

#define ll long long

#define ull unsigned long long

#define dll double

#define PI acos(-1)

#define watch(x) cout<<#x<<" = { "<<x<<" }\n"

#define sz(n) n.size()

#define M_Sayed fast() 

#define all(v) v.begin(),v.end()

#define allr(v) v.rbegin(),v.rend()

#define RT(v) return cout<<v,0

int dx[] = { 0, 1, 0, -1, 1, 1, -1, -1 };

int dy[] = { 1, 0, -1, 0, 1, -1, 1, -1 };

const double EPS = (1e-7);

ll Ceil(ll x, ll y) { return (x + y - 1) / y; }

void run() {

#ifndef ONLINE_JUDGE

	freopen("input.txt", "r", stdin);

	//freopen("output.txt", "w", stdout);

#else

#endif

}

ll gcd(ll a, ll b) { return !b ? abs(a) : gcd(b, a % b); }

ll lcm(ll a, ll b) { return abs(a / gcd(a, b)) * b; }

ll power(ll x, ll y, ll mod) {

	if (y == 0) return 1;

	if (y == 1) return x % mod;

	ll r = power(x, y >> 1, mod);

	return (((r * r) % mod) * power(x, y & 1, mod)) % mod;

}

void fast() { ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); }

ll n, m, k,su,cnt;

ll vis[100009];

vector<ll>v;

ll Jum(int x) {

	if (x+1 == n)

		return 0;

	ll &ret = vis[x];

	if (~ret)return ret;

	 ret = abs(v[x] - v[x + 1])+Jum(x + 1) ;

	for (int i = 2; i <=k; i++) {

		if(i+x<n)ret = min(ret,Jum(x + i) + abs(v[x] - v[x + i]));

	}

	return ret;

}

int main()

{

	//run();

	M_Sayed;

	cin >> n>>k ;

	memset(vis, -1, sizeof vis);

	v.resize(n);

	for (int i = 0; i <n; i++) {

		cin >> v[i];

	}

	RT(Jum(0));

}

// Optimized solution to the same problem (faster):
#include<bits/stdc++.h>

using namespace std;

int h[100001];

int dp[100001];

int n,k;

int solve(int stone)

{

    if(stone==n) return 0;

    if(dp[stone]!=-1) return dp[stone];

    int cost=1<<30;

    for(int i=1;i<=k and stone+i<=n;i++)

    cost=min( cost,abs(h[stone]-h[stone+i])+solve(stone+i) );



    return dp[stone]=cost;

}



int main()

{

    int i;

    scanf("%d %d",&n,&k);



    for(i=1; i<=n; i++)

        scanf("%d",&h[i]);



    memset(dp,-1,sizeof(dp));

    printf("%d\n",solve(1));





    return 0;

}




// Fastest known solution for this problem:
#include <iostream>

#include <array>

#include <vector>

#include <iomanip>

#include <string>

#include <cmath>

#include <array>

#include <algorithm>

#include <queue>

#include <map>

using namespace std;



typedef  pair<int,int> P;

typedef long long LL;



const LL  INF=1<<31;







int main(){

     int n,k;

     cin>>n>>k;

     int h[100000];

     for(int i=0;i<n;++i){

          cin>>h[i];

     }

     LL dp[100001];



      for(int i=0;i<n;++i){

           dp[i]=INF;

      }

            dp[0]=0;

            dp[1]=abs(h[0]-h[1]);







     for(int i=2;i<n;++i){

          dp[i]=dp[i-1]+abs(h[i-1]-h[i]);

          for(int j=2;j<=k;++j){



               if(j<=i)dp[i]=min(dp[i],dp[i-j]+abs(h[i-j]-h[i]));

          }

     }     



     cout<<dp[n-1]<<endl;





}