#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;
}

I2luY2x1ZGU8aW9zdHJlYW0+CiNpbmNsdWRlIDxiaXRzL3N0ZGMrKy5oPgoKdXNpbmcgbmFtZXNwYWNlIHN0ZDsKCmludCBtYWluKCl7CiAgCiAgaW50IG47CiAgY2luPj5uOwogIGludCBrOwogIGNpbj4+azsKICB2ZWN0b3I8aW50PiBhcnIobisxLDApOwogIAogIGZvcihpbnQgaT0xOyBpPD1uOyBpKyspewogICAgY2luPj5hcnJbaV07CiAgfQogIAogIHZlY3RvcjxpbnQ+IGRwKG4rMSwgMCk7CiAgCiAgZHBbMV0gPSAwOwogIGRwWzJdID0gYWJzKGFyclsxXSAtIGFyclsyXSk7CiAgCiAgaW50IGkgPSAzOwogIHdoaWxlKGk8PW4pewogICAgCiAgICBpbnQgYW5zPUlOVF9NQVg7CiAgICAKICAgIGZvcihpbnQgaj0xOyBqPGkgJiYgajw9azsgaisrKXsKICAgIAlhbnMgPSBtaW4oYW5zLCBkcFtpLWpdICsgYWJzKGFycltpXS1hcnJbaS1qXSkpOwogICAgfQogICAgZHBbaV09YW5zOwogICAgY291dDw8ICJmb3IgcG9zaXRpb24gIjw8aTw8IiBkcDotIjw8ZHBbaV07CiAgICBpKys7CiAgfQogIAogIGNvdXQgPDwgZHBbbl07CiAgcmV0dXJuIDA7Cn0=

NSAzCjEwIDMwIDQwIDUwIDIwCg==

5 3
10 30 40 50 20