import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    }

    public static int twoPower(int n  ,int[] arr){
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    }

    static class TaskA {
        public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }


    }
} import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.StringTokenizer; StringTokenizer java.util import java.io.IOException; IOException java.io import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.InputStream; InputStream java.io public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    }

    public static int twoPower(int n  ,int[] arr){
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    }

    static class TaskA {
        public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }


    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out InputReader in = new InputReader(inputStream); in new InputReader(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) TaskA solver = new TaskA(); solver new TaskA() solver.call(in,out) solver.call solver in out out.close() out.close out String[] args args public static int twoPower(int n  ,int[] arr){
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    } twoPower {
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    } int b; b int count=-1; count -1 1 b = arr.length-1 -n b arr.length-1 -n arr.length-1 -n arr.length arr arr.length 1 n while(b!=0){
            b/=2;
            count++;
        } b!=0 b 0 {
            b/=2;
            count++;
        } b/=2 b 2 count++ count return count; count int n n int[] arr arr static class TaskA {
        public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        }
    } TaskA public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        } call {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        } int b b n n k; k n=in.nextInt() n in.nextInt() in.nextInt in k=in.nextInt() k in.nextInt() in.nextInt in int[] arr = new int[n]; arr new int[n] n for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            } int i=0; int i=0; i 0 i<n i n i++ i++ i {
                arr[i]=in.nextInt();
            } {
                arr[i]=in.nextInt();
            } arr[i]=in.nextInt() arr[i] arr i in.nextInt() in.nextInt in int[] dp = new int[n]; dp new int[n] n for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            } int i=dp.length-2; int i=dp.length-2; i dp.length-2 dp.length dp dp.length 2 i>=0 i 0 i-- i-- i {
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            } {
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            } b=Integer.MAX_VALUE b Integer.MAX_VALUE Integer Integer.MAX_VALUE for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                } int j =1; int j =1; j 1 j+i<dp.length && j<=k j+i<dp.length j+i j i dp.length dp dp.length j<=k j k j++ j++ j {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                } {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                } int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i]; first Math.abs(arr[i] - arr[j+i]) + dp[j+i] Math.abs(arr[i] - arr[j+i]) Math.abs Math arr[i] - arr[j+i] arr[i] arr i arr[j+i] arr j+i j i dp[j+i] dp j+i j i if (first < b) {
                        b = first;
                    } first < b first b {
                        b = first;
                    } b = first b first dp[i] = b dp[i] dp i b out.println(dp[0]) out.println out dp[0] dp 0 InputReader in in PrintWriter out out static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }


    } InputReader public BufferedReader reader; reader public StringTokenizer tokenizer; tokenizer public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        } InputReader {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        } reader = new BufferedReader(new InputStreamReader(stream), 32768) reader new BufferedReader(new InputStreamReader(stream), 32768) tokenizer = null tokenizer null InputStream stream stream public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        } next {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        } while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            } try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                } IOException e {
                    throw new RuntimeException(e);
                } throw new RuntimeException(e); new RuntimeException(e) {
                    tokenizer = new StringTokenizer(reader.readLine());
                } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public int nextInt() {
            return Integer.parseInt(next());
        } nextInt {
            return Integer.parseInt(next());
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public long nextLong() {
            return Long.parseLong(next());
        } nextLong {
            return Long.parseLong(next());
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    }

    public static int twoPower(int n  ,int[] arr){
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    }

    static class TaskA {
        public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }


    }
} public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    }

    public static int twoPower(int n  ,int[] arr){
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    }

    static class TaskA {
        public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }


    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.call(in,out);
        out.close();
    }

    public static int twoPower(int n  ,int[] arr){
        int b;
        int count=-1;
        b = arr.length-1 -n;
        while(b!=0){
            b/=2;
            count++;
        }
        return count;
    }

    static class TaskA {
        public void call(InputReader in, PrintWriter out ) {
            int b , n  , k;
            n=in.nextInt();
            k=in.nextInt();
            int[] arr = new int[n];
            for(int i=0;i<n;i++){
                arr[i]=in.nextInt();
            }

            int[] dp = new int[n];

            for(int i=dp.length-2; i>=0;i--){
                b=Integer.MAX_VALUE;
                for (int j =1;j+i<dp.length && j<=k;j++)  {
                    int first = Math.abs(arr[i] - arr[j+i]) + dp[j+i];
                    if (first < b) {
                        b = first;
                    }

                }
                dp[i] = b ;
            }
            out.println(dp[0]);
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }


    }
}
