description: A total of n depots are located on a number line. Depot i lies at the point x_i for 1 ≤ i ≤ n.
  
  You are a salesman with n bags of goods, attempting to deliver one bag to each of the n depots. You and the n bags are initially at the origin 0. You can carry up to k bags at a time. You must collect the required number of goods from the origin, deliver them to the respective depots, and then return to the origin to collect your next batch of goods.
  
  Calculate the minimum distance you need to cover to deliver all the bags of goods to the depots. You do not have to return to the origin after you have delivered all the bags.
  
  Input
  
  Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 10 500). Description of the test cases follows.
  
  The first line of each test case contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5).
  
  The second line of each test case contains n integers x_1, x_2, …, x_n (-10^9 ≤ x_i ≤ 10^9). It is possible that some depots share the same position.
  
  It is guaranteed that the sum of n over all test cases does not exceed 2 ⋅ 10^5.
  
  Output
  
  For each test case, output a single integer denoting the minimum distance you need to cover to deliver all the bags of goods to the depots. 
  
  Example
  
  Input
  
  
  4
  5 1
  1 2 3 4 5
  9 3
  -5 -10 -15 6 5 8 3 7 4
  5 3
  2 2 3 3 3
  4 2
  1000000000 1000000000 1000000000 1000000000
  
  
  Output
  
  
  25
  41
  7
  3000000000
  
  Note
  
  In the first test case, you can carry only one bag at a time. Thus, the following is a solution sequence that gives a minimum travel distance: 0 → 2 → 0 → 4 → 0 → 3 → 0 → 1 → 0 → 5, where each 0 means you go the origin and grab one bag, and each positive integer means you deliver the bag to a depot at this coordinate, giving a total distance of 25 units. It must be noted that there are other sequences that give the same distance.
  
  In the second test case, you can follow the following sequence, among multiple such sequences, to travel minimum distance: 0 → 6 → 8 → 7 → 0 → 5 → 4 → 3 → 0 → (-5) → (-10) → (-15), with distance 41. It can be shown that 41 is the optimal distance for this test case.
solution: import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.PrintWriter;
  import java.math.BigInteger;
  import java.util.*;
  
  /**
   * @author Mubtasim Shahriar
   */
  
  public class MinimizeDistance {
  
      public static void main(String[] args) {
  
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader sc = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          Solver solver = new Solver();
          int t = sc.nextInt();
  //        int t = 1;
          while (t-- != 0) {
              solver.solve(sc, out);
          }
          out.close();
  
      }
  
      static class Solver {
          public void solve(InputReader sc, PrintWriter out) {
              int n = sc.nextInt();
              int k = sc.nextInt();
              ArrayList<Long> left = new ArrayList<>();
              ArrayList<Long> right = new ArrayList<>();
              long[] arr = sc.nextLongArray(n);
              for(long l : arr) {
                  if(l==0) continue;
                  if(l>0) right.add(l);
                  else left.add(Math.abs(l));
              }
              Collections.sort(left);
              Collections.sort(right);
              long leftMinus = getAns(single(left,k) + getDouble(removee(left,k),right,k));
              long rightMinus = getAns(single(right,k) + getDouble(removee(right,k),left,k));
              long ans = Math.min(leftMinus,rightMinus);
              out.println(ans);
          }
  
          private long getAns(long l) {
              return l;
          }
  
          private long single(ArrayList<Long> left, int k) {
              if(left.isEmpty()) return 0;
              return left.get(left.size()-1);
          }
  
          private long getDouble(ArrayList<Long> left, ArrayList<Long> right, int k) {
              long total = getOps(left,k) + getOps(right,k);
              return total;
          }
  
          private long getOps(ArrayList<Long> list, int k) {
              int idx = list.size()-1;
              long ret = 0;
              while(idx>=0) {
                  long val = list.get(idx);
                  idx -= k;
                  ret += val*2;
              }
              return ret;
          }
  
          private ArrayList<Long> removee(ArrayList<Long> left, int k) {
              ArrayList<Long> ret = new ArrayList<>();
              int n = left.size();
              long upto = n-k;
              for(int i = 0; i < upto; i++) ret.add(left.get(i));
              return ret;
          }
      }
  
      static void sort(int[] arr) {
          ArrayList<Integer> al = new ArrayList();
          for (int i : arr) al.add(i);
          Collections.sort(al);
          int idx = 0;
          for (int i : al) arr[idx++] = i;
      }
  
      static void sort(long[] arr) {
          ArrayList<Long> al = new ArrayList();
          for (long i : arr) al.add(i);
          Collections.sort(al);
          int idx = 0;
          for (long i : al) arr[idx++] = i;
      }
  
      static void sortDec(int[] arr) {
          ArrayList<Integer> al = new ArrayList();
          for (int i : arr) al.add(i);
          Collections.sort(al, Collections.reverseOrder());
          int idx = 0;
          for (int i : al) arr[idx++] = i;
      }
  
      static void sortDec(long[] arr) {
          ArrayList<Long> al = new ArrayList();
          for (long i : arr) al.add(i);
          Collections.sort(al, Collections.reverseOrder());
          int idx = 0;
          for (long i : al) arr[idx++] = i;
      }
  
      static class InputReader {
          private boolean finished = false;
  
          private InputStream stream;
          private byte[] buf = new byte[1024];
          private int curChar;
          private int numChars;
          private SpaceCharFilter filter;
  
          public InputReader(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 peek() {
              if (numChars == -1) {
                  return -1;
              }
              if (curChar >= numChars) {
                  curChar = 0;
                  try {
                      numChars = stream.read(buf);
                  } catch (IOException e) {
                      return -1;
                  }
                  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 long nextLong() {
              int c = read();
              while (isSpaceChar(c)) {
                  c = read();
              }
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              long 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 String nextString() {
              int c = read();
              while (isSpaceChar(c)) {
                  c = read();
              }
              StringBuilder res = new StringBuilder();
              do {
                  if (Character.isValidCodePoint(c)) {
                      res.appendCodePoint(c);
                  }
                  c = read();
              } while (!isSpaceChar(c));
              return res.toString();
          }
  
          public boolean isSpaceChar(int c) {
              if (filter != null) {
                  return filter.isSpaceChar(c);
              }
              return isWhitespace(c);
          }
  
          public static boolean isWhitespace(int c) {
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
          private String readLine0() {
              StringBuilder buf = new StringBuilder();
              int c = read();
              while (c != '\n' && c != -1) {
                  if (c != '\r') {
                      buf.appendCodePoint(c);
                  }
                  c = read();
              }
              return buf.toString();
          }
  
          public String readLine() {
              String s = readLine0();
              while (s.trim().length() == 0) {
                  s = readLine0();
              }
              return s;
          }
  
          public String readLine(boolean ignoreEmptyLines) {
              if (ignoreEmptyLines) {
                  return readLine();
              } else {
                  return readLine0();
              }
          }
  
          public BigInteger readBigInteger() {
              try {
                  return new BigInteger(nextString());
              } catch (NumberFormatException e) {
                  throw new InputMismatchException();
              }
          }
  
          public char nextCharacter() {
              int c = read();
              while (isSpaceChar(c)) {
                  c = read();
              }
              return (char) c;
          }
  
          public double nextDouble() {
              int c = read();
              while (isSpaceChar(c)) {
                  c = read();
              }
              int sgn = 1;
              if (c == '-') {
                  sgn = -1;
                  c = read();
              }
              double res = 0;
              while (!isSpaceChar(c) && c != '.') {
                  if (c == 'e' || c == 'E') {
                      return res * Math.pow(10, nextInt());
                  }
                  if (c < '0' || c > '9') {
                      throw new InputMismatchException();
                  }
                  res *= 10;
                  res += c - '0';
                  c = read();
              }
              if (c == '.') {
                  c = read();
                  double m = 1;
                  while (!isSpaceChar(c)) {
                      if (c == 'e' || c == 'E') {
                          return res * Math.pow(10, nextInt());
                      }
                      if (c < '0' || c > '9') {
                          throw new InputMismatchException();
                      }
                      m /= 10;
                      res += (c - '0') * m;
                      c = read();
                  }
              }
              return res * sgn;
          }
  
          public boolean isExhausted() {
              int value;
              while (isSpaceChar(value = peek()) && value != -1) {
                  read();
              }
              return value == -1;
          }
  
          public String next() {
              return nextString();
          }
  
          public SpaceCharFilter getFilter() {
              return filter;
          }
  
          public void setFilter(SpaceCharFilter filter) {
              this.filter = filter;
          }
  
          public interface SpaceCharFilter {
              public boolean isSpaceChar(int ch);
          }
  
          public int[] nextIntArray(int n) {
              int[] array = new int[n];
              for (int i = 0; i < n; ++i) array[i] = nextInt();
              return array;
          }
  
          public int[] nextSortedIntArray(int n) {
              int array[] = nextIntArray(n);
              Arrays.sort(array);
              return array;
          }
  
          public int[] nextSumIntArray(int n) {
              int[] array = new int[n];
              array[0] = nextInt();
              for (int i = 1; i < n; ++i) array[i] = array[i - 1] + nextInt();
              return array;
          }
  
          public long[] nextLongArray(int n) {
              long[] array = new long[n];
              for (int i = 0; i < n; ++i) array[i] = nextLong();
              return array;
          }
  
          public long[] nextSumLongArray(int n) {
              long[] array = new long[n];
              array[0] = nextInt();
              for (int i = 1; i < n; ++i) array[i] = array[i - 1] + nextInt();
              return array;
          }
  
          public long[] nextSortedLongArray(int n) {
              long array[] = nextLongArray(n);
              Arrays.sort(array);
              return array;
          }
      }
  
  
  }
  