import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {

	int mod = 1000000007;

	static public int diff(int[] a, int i, int j) {
		return Math.abs(a[i] - a[j]);
	}

	public static void main(String[] args) {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	}

	// -----------PrintWriter for faster output---------------------------------
	public static PrintWriter out;

	// -----------MyScanner class for faster input----------
	public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			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.io.BufferedOutputStream; BufferedOutputStream java.io import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.PrintWriter; PrintWriter java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {

	int mod = 1000000007;

	static public int diff(int[] a, int i, int j) {
		return Math.abs(a[i] - a[j]);
	}

	public static void main(String[] args) {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	}

	// -----------PrintWriter for faster output---------------------------------
	public static PrintWriter out;

	// -----------MyScanner class for faster input----------
	public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			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 int mod = 1000000007; mod 1000000007 // -----------PrintWriter for faster output---------------------------------
	public static PrintWriter out; out static public int diff(int[] a, int i, int j) {
		return Math.abs(a[i] - a[j]);
	} diff {
		return Math.abs(a[i] - a[j]);
	} return Math.abs(a[i] - a[j]); Math.abs(a[i] - a[j]) Math.abs Math a[i] - a[j] a[i] a i a[j] a j int[] a a int i i int j j public static void main(String[] args) {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	} main {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	} MyScanner sc = new MyScanner(); sc new MyScanner() out = new PrintWriter(new BufferedOutputStream(System.out)) out new PrintWriter(new BufferedOutputStream(System.out)) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int k = sc.nextInt(); k sc.nextInt() sc.nextInt sc int[] a = new int[n]; a new int[n] n for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			a[i] = sc.nextInt();
		} {
			a[i] = sc.nextInt();
		} a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc int[] dp = new int[n]; dp new int[n] n for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		} int i = 0; int i = 0; i 0 i < k && i < n i < k i k i < n i n i++ i++ i {
			dp[i] = diff(a, 0, i);
		} {
			dp[i] = diff(a, 0, i);
		} dp[i] = diff(a, 0, i) dp[i] dp i diff(a, 0, i) diff a 0 i for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		} int i = k; int i = k; i k i < n i n i++ i++ i {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		} {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		} dp[i] = Integer.MAX_VALUE dp[i] dp i Integer.MAX_VALUE Integer Integer.MAX_VALUE for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			} int j = 1; int j = 1; j 1 j <= k j k j++ j++ j {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			} {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			} dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]) dp[i] dp i Math.min(dp[i], diff(a, i, i - j) + dp[i - j]) Math.min Math dp[i] dp i diff(a, i, i - j) + dp[i - j] diff(a, i, i - j) diff a i i - j i j dp[i - j] dp i - j i j out.print(dp[n - 1]) out.print out dp[n - 1] dp n - 1 n 1 out.close() out.close out String[] args args public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			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;
		}

	} MyScanner BufferedReader br; br StringTokenizer st; st public MyScanner() {
			br = new BufferedReader(new InputStreamReader(System.in));
		} MyScanner {
			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 public class Main {

	int mod = 1000000007;

	static public int diff(int[] a, int i, int j) {
		return Math.abs(a[i] - a[j]);
	}

	public static void main(String[] args) {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	}

	// -----------PrintWriter for faster output---------------------------------
	public static PrintWriter out;

	// -----------MyScanner class for faster input----------
	public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			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;
		}

	}
	// --------------------------------------------------------
} public class Main {

	int mod = 1000000007;

	static public int diff(int[] a, int i, int j) {
		return Math.abs(a[i] - a[j]);
	}

	public static void main(String[] args) {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	}

	// -----------PrintWriter for faster output---------------------------------
	public static PrintWriter out;

	// -----------MyScanner class for faster input----------
	public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			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
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {

	int mod = 1000000007;

	static public int diff(int[] a, int i, int j) {
		return Math.abs(a[i] - a[j]);
	}

	public static void main(String[] args) {
		MyScanner sc = new MyScanner();
		out = new PrintWriter(new BufferedOutputStream(System.out));

		int n = sc.nextInt();
		int k = sc.nextInt();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}

		int[] dp = new int[n];
		for (int i = 0; i < k && i < n; i++) {
			dp[i] = diff(a, 0, i);
		}

		for (int i = k; i < n; i++) {
			dp[i] = Integer.MAX_VALUE;
			for (int j = 1; j <= k; j++) {
				dp[i] = Math.min(dp[i], diff(a, i, i - j) + dp[i - j]);
			}
		}

		out.print(dp[n - 1]);
		/*
		 * int n = sc.nextInt(); // read input as integer long k = sc.nextLong(); //
		 * read input as long double d = sc.nextDouble(); // read input as double String
		 * str = sc.next(); // read input as String String s = sc.nextLine(); // read
		 * whole line as String
		 * 
		 * int result = 3*n; out.println(result); // print via PrintWriter
		 */

		// Stop writing your solution here. -------------------------------------
		out.close();
	}

	// -----------PrintWriter for faster output---------------------------------
	public static PrintWriter out;

	// -----------MyScanner class for faster input----------
	public static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() {
			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;
		}

	}
	// --------------------------------------------------------
}
