#include <cassert>

#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
//#include <boost/foreach.hpp>
//#include <boost/range/algorithm.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
#define INF 1e9
#define LINF 1e18
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define MOD 1000000007LL
#define int long long
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
struct edge{int to,cost;};
typedef pair<int,int> P;

bool isupper(char c){if('A'<=c&&c<='Z')return 1;return 0;}
bool islower(char c){if('a'<=c&&c<='z')return 1;return 0;}
bool isPrime(int x){if(x==1)return 0;if(x==2)return 1;if(x%2==0)return 0;for(int i=3;i*i<=x;i++)if(x%i==0)return 0;return 1;}
bool iskaibun(string s){for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-i-1])return 0;return 1;}

signed main (){
    // int n,c;cin>>n>>c;
    // vector<vector<int>> v(3,vector<int>(c)),cost(c,vector<int>(c));
    // rep(i,0,n)rep(j,0,n){
    //     int x;cin>>x;
    //     v[(i+j)%3][x-1]++;
    // }
    // rep(i,0,c)rep(j,0,c)cin>>cost[i][j];

    // int ans=1e18;
    // rep(i,0,c){ //%3==0をiに
    //     rep(j,0,c){  //%3==1をjに
    //         if(i==j)continue;
    //         rep(k,0,c){ //%3==2をkにするとき
    //             if(i==k || j==k)continue; 
    //             int ret=0;
    //             rep(ind,0,3){
    //                 int x;
    //                 if(ind==0)x=i;
    //                 else if(ind==1)x=j;
    //                 else if(ind==2)x=k;
    //                 rep(val,0,c){
    //                     ret+=v[ind][val]*cost[val][x];
    //                 }
    //             }
    //             ans=min(ans,ret);
    //         }
    //     }
    // }
    // cout<<ans<<endl;
    int n,k;cin>>n>>k;
    vector<int> h(n);
    vector<int> dp(n+1,1e18);
    dp[0]=0;
    rep(i,1,k+1)dp[i]=abs(h[i]-h[0]);
    rep(i,0,n)cin>>h[i];
    rep(i,1,n){
        int res=1e18;
        rep(j,1,k+1){
            if(i-j<0)break;
            res=min(res,dp[i-j]+abs(h[i]-h[i-j]));
        }
        dp[i]=res;
    }
    cout<<dp[n-1]<<endl;
    

    


}
/*

*/


Measured memory_bytes: 1792