import java.util.*;
import java.io.*;

class Main {

     public static void main(String []args){
        FastReader sc = new FastReader();
        
        int n = sc.nextInt(), k = sc.nextInt();
        int [] heights = new int [n];
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        }
        int [] dp = new int [n];
        
        for (int i = 1; i < n; i++) {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        }
        
        System.out.println(dp[n - 1]);
     }
     
     static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
  
} import java.util.*; util.* java import java.io.*; io.* java class Main {

     public static void main(String []args){
        FastReader sc = new FastReader();
        
        int n = sc.nextInt(), k = sc.nextInt();
        int [] heights = new int [n];
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        }
        int [] dp = new int [n];
        
        for (int i = 1; i < n; i++) {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        }
        
        System.out.println(dp[n - 1]);
     }
     
     static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
  
} Main public static void main(String []args){
        FastReader sc = new FastReader();
        
        int n = sc.nextInt(), k = sc.nextInt();
        int [] heights = new int [n];
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        }
        int [] dp = new int [n];
        
        for (int i = 1; i < n; i++) {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        }
        
        System.out.println(dp[n - 1]);
     } main {
        FastReader sc = new FastReader();
        
        int n = sc.nextInt(), k = sc.nextInt();
        int [] heights = new int [n];
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        }
        int [] dp = new int [n];
        
        for (int i = 1; i < n; i++) {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        }
        
        System.out.println(dp[n - 1]);
     } FastReader sc = new FastReader(); sc new FastReader() int n = sc.nextInt() n sc.nextInt() sc.nextInt sc k = sc.nextInt(); k sc.nextInt() sc.nextInt sc int [] heights = new int [n]; heights new int [n] n for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            heights[i] = sc.nextInt();
        } {
            heights[i] = sc.nextInt();
        } heights[i] = sc.nextInt() heights[i] heights i sc.nextInt() sc.nextInt sc int [] dp = new int [n]; dp new int [n] n for (int i = 1; i < n; i++) {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        } {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        } dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]) dp[i] dp i dp[i - 1] + Math.abs(heights[i] - heights[i - 1]) dp[i - 1] dp i - 1 i 1 Math.abs(heights[i] - heights[i - 1]) Math.abs Math heights[i] - heights[i - 1] heights[i] heights i heights[i - 1] heights i - 1 i 1 for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            } int j = i - 2; int j = i - 2; j i - 2 i 2 j >= Math.max(0, i - k) j Math.max(0, i - k) Math.max Math 0 i - k i k j-- j-- j {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            } {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            } dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j])) dp[i] dp i Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j])) Math.min Math dp[i] dp i dp[j] + Math.abs(heights[i] - heights[j]) dp[j] dp j Math.abs(heights[i] - heights[j]) Math.abs Math heights[i] - heights[j] heights[i] heights i heights[j] heights j System.out.println(dp[n - 1]) System.out.println System.out System System.out dp[n - 1] dp n - 1 n 1 String []args args static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } FastReader BufferedReader br; br StringTokenizer st; st public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } FastReader { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } br = new BufferedReader(new
                     InputStreamReader(System.in)) br new BufferedReader(new
                     InputStreamReader(System.in)) String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } next { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } st == null || !st.hasMoreElements() st == null st null !st.hasMoreElements() st.hasMoreElements() st.hasMoreElements st { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } IOException  e { 
                    e.printStackTrace(); 
                } e.printStackTrace() e.printStackTrace e { 
                    st = new StringTokenizer(br.readLine()); 
                } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } nextInt { 
            return Integer.parseInt(next()); 
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next long nextLong() 
        { 
            return Long.parseLong(next()); 
        } nextLong { 
            return Long.parseLong(next()); 
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } nextDouble { 
            return Double.parseDouble(next()); 
        } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } nextLine { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } String str = ""; str "" try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } catch (IOException e) 
            { 
                e.printStackTrace(); 
            } IOException e { 
                e.printStackTrace(); 
            } e.printStackTrace() e.printStackTrace e { 
                str = br.readLine(); 
            } str = br.readLine() str br.readLine() br.readLine br return str; str
import java.util.*;
import java.io.*;

class Main {

     public static void main(String []args){
        FastReader sc = new FastReader();
        
        int n = sc.nextInt(), k = sc.nextInt();
        int [] heights = new int [n];
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        }
        int [] dp = new int [n];
        
        for (int i = 1; i < n; i++) {
            dp[i] = dp[i - 1] + Math.abs(heights[i] - heights[i - 1]);
            for (int j = i - 2; j >= Math.max(0, i - k); j--) {
                dp[i] = Math.min(dp[i], dp[j] + Math.abs(heights[i] - heights[j]));
            }
        }
        
        System.out.println(dp[n - 1]);
     }
     
     static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
  
}