#include<iostream>
#include <bits/stdc++.h>

using namespace std;

int main(){
  
  int n;
  cin>>n;
  int k;
  cin>>k;
  vector<int> arr(n+1,0);
  
  for(int i=1; i<=n; i++){
    cin>>arr[i];
  }
  
  vector<int> dp(n+1, 0);
  
  dp[1] = 0;
  dp[2] = abs(arr[1] - arr[2]);
  
  int i = 3;
  while(i<=n){
    
    int ans=INT_MAX;
    
    for(int j=1; j<i && j<=k; j++){
    	ans = min(ans, dp[i-j] + abs(arr[i]-arr[i-j]));
    }
    dp[i]=ans;
    cout<< "for position "<<i<<" dp:-"<<dp[i];
    i++;
  }
  
  cout << dp[n];
  return 0;
}