import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Pranay2516
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        }

    }

    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}
 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.Arrays; Arrays java.util import java.util.InputMismatchException; InputMismatchException java.util import java.io.IOException; IOException 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;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        }

    }

    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out FastReader in = new FastReader(inputStream); in new FastReader(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) Task solver = new Task(); solver new Task() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class Task {
        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        }

    } Task public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        } solve {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        } int n = in.nextInt() n in.nextInt() in.nextInt in k = in.nextInt() k in.nextInt() in.nextInt in h[] = in.readIntArray(n) h in.readIntArray(n) in.readIntArray in n cost[] = new int[n]; cost new int[n] n Arrays.fill(cost, (int) Math.pow(10, 9) + 5) Arrays.fill Arrays cost (int) Math.pow(10, 9) + 5 (int) Math.pow(10, 9) Math.pow Math 10 9 5 cost[0] = 0 cost[0] cost 0 0 for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i])); int i = 0; int i = 0; i 0 i < n i n ++i ++i i for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i])); for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i])); int j = i + 1; int j = i + 1; j i + 1 i 1 j <= i + k && j < n j <= i + k j i + k i k j < n j n ++j ++j j cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i])); cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i])) cost[j] cost j Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i])) Math.min Math cost[j] cost j cost[i] + Math.abs(h[j] - h[i]) cost[i] cost i Math.abs(h[j] - h[i]) Math.abs Math h[j] - h[i] h[j] h j h[i] h i out.println(cost[n - 1]) out.println out cost[n - 1] cost n - 1 n 1 int testNumber testNumber FastReader in in PrintWriter out out static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    } FastReader private InputStream stream; stream private byte[] buf = new byte[1024]; buf new byte[1024] 1024 private int curChar; curChar private int numChars; numChars private FastReader.SpaceCharFilter filter; filter public FastReader(InputStream stream) {
            this.stream = stream;
        } FastReader {
            this.stream = stream;
        } this.stream = stream this.stream this this.stream stream InputStream stream stream public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        } read {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        } if (numChars == -1) throw new InputMismatchException(); numChars == -1 numChars -1 1 throw new InputMismatchException(); new InputMismatchException() if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            } curChar >= numChars curChar numChars {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            } curChar = 0 curChar 0 try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                } catch (IOException e) {
                    throw new InputMismatchException();
                } IOException e {
                    throw new InputMismatchException();
                } throw new InputMismatchException(); new InputMismatchException() {
                    numChars = stream.read(buf);
                } numChars = stream.read(buf) numChars stream.read(buf) stream.read stream buf if (numChars <= 0) return -1; numChars <= 0 numChars 0 return -1; -1 1 return buf[curChar++]; buf[curChar++] buf curChar++ curChar public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        } nextInt {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        } int c = read(); c read() read while (isSpaceChar(c)) c = read(); isSpaceChar(c) isSpaceChar c c = read() c read() read int sgn = 1; sgn 1 if (c == '-') {
                sgn = -1;
                c = read();
            } c == '-' c '-' {
                sgn = -1;
                c = read();
            } sgn = -1 sgn -1 1 c = read() c read() read int res = 0; res 0 do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c)); !isSpaceChar(c) isSpaceChar(c) isSpaceChar c {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } if (c < '0' || c > '9') throw new InputMismatchException(); c < '0' || c > '9' c < '0' c '0' c > '9' c '9' throw new InputMismatchException(); new InputMismatchException() res *= 10 res 10 res += c - '0' res c - '0' c '0' c = read() c read() read return res * sgn; res * sgn res sgn public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        } isSpaceChar {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        } if (filter != null) return filter.isSpaceChar(c); filter != null filter null return filter.isSpaceChar(c); filter.isSpaceChar(c) filter.isSpaceChar filter c return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1 c == '\t' c == '\r' c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1 c == ' ' c ' ' c == '\n' c '\n' c == '\r' c '\r' c == '\t' c '\t' c == -1 c -1 1 int c c public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        } readIntArray {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        } int[] array = new int[(int) size]; array new int[(int) size] (int) size for (int i = 0; i < size; i++) array[i] = nextInt(); int i = 0; int i = 0; i 0 i < size i size i++ i++ i array[i] = nextInt(); array[i] = nextInt() array[i] array i nextInt() nextInt return array; array int size size public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        } SpaceCharFilter public boolean isSpaceChar(int ch); isSpaceChar int ch ch public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        }

    }

    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        }

    }

    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Pranay2516
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = in.nextInt(), k = in.nextInt(), h[] = in.readIntArray(n), cost[] = new int[n];
            Arrays.fill(cost, (int) Math.pow(10, 9) + 5);
            cost[0] = 0;
            for (int i = 0; i < n; ++i)
                for (int j = i + 1; j <= i + k && j < n; ++j)
                    cost[j] = Math.min(cost[j], cost[i] + Math.abs(h[j] - h[i]));
            out.println(cost[n - 1]);
        }

    }

    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastReader.SpaceCharFilter filter;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int[] readIntArray(int size) {
            int[] array = new int[(int) size];
            for (int i = 0; i < size; i++) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}

