#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define MOD1 1000000007
#define MOD2 998244353
#define NO cout << "NO" << endl
#define YES cout << "YES" << endl
ll expo(ll a, ll b, ll mod) {ll res = 1; while (b > 0) {if (b & 1)res = (res * a) % mod; a = (a * a) % mod; b = b >> 1;} return res;}
ll mminvprime(ll a, ll b) {return expo(a, b - 2, b);}
ll mod_add(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a + b) % m) + m) % m;}
ll mod_mul(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a * b) % m) + m) % m;}
ll mod_sub(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a - b) % m) + m) % m;}
ll mod_div(ll a, ll b, ll m) {a = a % m; b = b % m; return (mod_mul(a, mminvprime(b, m), m) + m) % m;}
void print(vector<int> &ans){for(auto x: ans) cout<<x<<" "; cout<<endl;}

// ========================================================================================================================================================================================================


int memo(int n,int k,vector<int> &heights,vector<int> &dp,int ind)
{
    if(ind==0)
        return 0;
    if(dp[ind]!=-1)
        return dp[ind];
    int mini=INT_MAX;
    for(int i=1;i<=k;i++)
    {
        if(ind-i>=0)
            mini=min(mini,memo(n,k,heights,dp,ind-i)+abs(heights[ind-i]-heights[ind]));

    }

    dp[ind]=mini;

    return dp[ind];
}


int tabularization(int n,int k,vector<int> &heights,vector<int> &dp)
{
    dp[0]=0;
    dp[1]=min(heights[1],abs(heights[1]-heights[0]));

    for(int ind=2;ind<n;ind++)
    {
        int mini=INT_MAX;
        for(int i=1;i<=k;i++)
        {
            if(ind-i>=0)
                mini=min(mini,dp[ind-i]+abs(heights[ind-i]-heights[ind]));
        }
        dp[ind]=mini;
    }
    return dp[n-1];
}
void solve()
{

    int n,k;
    cin>>n>>k;
    vector<int> heights;
    vector<int> dp(n,-1);

    for(int i=0;i<n;i++)
    {
        int h;cin>>h;
        heights.pb(h);
    }

    // cout<<memo(n,k,heights,dp,n-1)<<endl;
    cout<<tabularization(n,k,heights,dp)<<endl;

}


int main()
{

  solve();
}