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.util.*;
  import java.io.*;
  import java.math.*;
  
  
  /**
   * @author Naitik
   * 
   */
  public class Main
  
  { 
  	 static FastReader sc=new FastReader(); 
  	 static long dp[];
  	 //static int v[][];
  //	 static int mod=998244353;;
  	 static int mod=1000000007;
  	 static int max;
  	 static int bit[];
  	 //static long fact[];
  //	 static long A[];
  	// static TreeMap<Integer,Integer> map;
  	 //static StringBuffer sb=new StringBuffer("");
  	 static HashMap<Integer,Integer> map;
  	   static PrintWriter out=new PrintWriter(System.out);
  	  public static void main(String[] args)
  	  {
  		 //  StringBuffer sb=new StringBuffer("");
  		  int ttt=1;
  		       ttt =i();	
  	        outer :while (ttt-- > 0) 
  			{
  	        	int n=i();
  	        	int k=i();
  	        	long A[]=inputL(n);
  	        	ArrayList<Long> l=new ArrayList<Long>();
  	        	ArrayList<Long> m=new ArrayList<Long>();
  	        	ArrayList<Long> l1=new ArrayList<Long>();
  	        	ArrayList<Long> m1=new ArrayList<Long>();
  	        	for(long i : A) {
  	        		if(i>0) {
  	        			l.add(i);
  	        		}
  	        		else if(i<0) {
  	        			m.add(-i);
  	        		}
  	        	}
  	        	l.sort(null);
  	        	m.sort(null);
  	        	long ans1=0;
  	        	long ans2=0;
  	        	int pv=k;
  	        	for(int i=l.size()-1;i>=0;i-=k) {
  	        		if(i==l.size()-1) {
  	        			ans1+=l.get(i);
  	        		}
  	        		else {
  	        			ans1+=2*l.get(i);
  	        		}
  	        	}
  	        	for(int i=m.size()-1;i>=0;i-=k) {
  	        		if(i==m.size()-1) {
  	        			ans2+=m.get(i);
  	        		}
  	        		else {
  	        			ans2+=2*m.get(i);
  	        		}
  	        	}
  	        	if(l.size()==0) {
  	        		out.println(ans2);
  	        	}
  	        	else if(m.size()==0) {
  	        		out.println(ans1);
  	        	}
  	        	else {
  	        		out.println(ans1+ans2+min(l.get(l.size()-1),m.get(m.size()-1)));
  	        	}
  
  	        	
  	        }
  	        //System.out.println(sb.toString());
  		     out.close();
  	     
  	     
  	    //CHECK FOR N=1                    //CHECK FOR M=0
          //CHECK FOR N=1                    //CHECK FOR M=0
         	//CHECK FOR N=1
         	
  		        
  		     
      }
  	 
  	 
  	  
  static class Pair implements Comparable<Pair>
       {
      	 int x;
      	 int y;
      	 int z;
      	 Pair(int x,int y,int z){
      		 this.x=x;
      		 this.y=y;
      		 this.z=z;
      		 
      	 }
  		@Override
  		public int compareTo(Pair o) {
  			if(this.x>o.x)
  				return 1;
  			else if(this.x<o.x)
  				return -1;
  			else {
  				if(this.y>o.y)
  					return 1;
  				else if(this.y<o.y)
  					return -1;
  				else
  					return 0;
  			}
  		}
  //		public int hashCode() 
  //		{ 
  //			final int temp = 14; 
  //			int ans = 1; 
  //			ans =x*31+y*13; 
  //			return ans; 
  //		} 
  //		@Override
  //		public boolean equals(Object o) 
  //		{ 
  //			if (this == o) { 
  //				return true; 
  //			} 
  //			if (o == null) { 
  //				return false; 
  //			} 
  //			if (this.getClass() != o.getClass()) { 
  //				return false; 
  //			} 
  //			Pair other = (Pair)o; 
  //			if (this.x != other.x || this.y!=other.y) { 
  //				return false; 
  //			} 
  //			return true; 
  //		} 	
  //		
  		/* FOR TREE MAP PAIR USE */
  		
  //		public int compareTo(Pair o) {
  // 			if (x > o.x) {
  // 				return 1;
  // 			}
  // 			if (x < o.x) {
  // 				return -1;
  // 			}
  // 			if (y > o.y) {
  // 				return 1;
  // 			}
  // 			if (y < o.y) {
  // 				return -1;
  // 			}
  // 			return 0;
  // 		}
  		
       }
  
  static int find(int A[],int a) {
  	  if(A[a]==a)
  		  return a;
  	  return A[a]=find(A, A[a]);
  }
  //static int find(int A[],int a) {
  //	  if(A[a]==a)
  //		  return a;
  //	  return find(A, A[a]);
  //}
  //FENWICK TREE
  static void update(int i, int x){
  	for(; i < bit.length; i += (i&-i))
  		bit[i] += x;
  }
  
  static int sum(int i){
  	int ans = 0;
  	for(; i > 0; i -= (i&-i))
  		ans += bit[i];
  	return ans;
  }
  //END
  static void add(int v) {
  	if(!map.containsKey(v)) {
  		map.put(v, 1);
  	}
  	else {
  		map.put(v, map.get(v)+1);
  	}
  }
  static void remove(int v) {
  	if(map.containsKey(v)) {
  		map.put(v, map.get(v)-1);
  		if(map.get(v)==0)
  			map.remove(v);
  	}
  }
  public static int upper(int A[],int k,int si,int ei)
  {
  	int l=si;
  	int u=ei;
  	int ans=-1;
  	while(l<=u) {
  		int mid=(l+u)/2;
  		if(A[mid]<=k) {
  			ans=mid;
  			l=mid+1;
  		}
  		else {
  			u=mid-1;
  		}
  	}
  	return ans;
  }
  public static int lower(int A[],int k,int si,int ei)
  {
  	int l=si;
  	int u=ei;
  	int ans=-1;
  	while(l<=u) {
  		int mid=(l+u)/2;
  		if(A[mid]<=k) {
  			l=mid+1;
  		}
  		else {
  			ans=mid;
  			u=mid-1;
  		}
  	}
  	return ans;
  	
      
  }
  static int[] copy(int A[]) {
  	int B[]=new int[A.length];
  	for(int i=0;i<A.length;i++) {
  		B[i]=A[i];
  	}
  	return B;
  }
  static long[] copy(long A[]) {
  	long B[]=new long[A.length];
  	for(int i=0;i<A.length;i++) {
  		B[i]=A[i];
  	}
  	return B;
  }
  static int[] input(int n) {
  	int A[]=new int[n];
  	   for(int i=0;i<n;i++) {
  		   A[i]=sc.nextInt();
  	   }
  	   return A;
     }
  static long[] inputL(int n) {
  	long A[]=new long[n];
  	   for(int i=0;i<n;i++) {
  		   A[i]=sc.nextLong();
  	   }
  	   return A;
     }
  static String[] inputS(int n) {
  	String A[]=new String[n];
  	   for(int i=0;i<n;i++) {
  		   A[i]=sc.next();
  	   }
  	   return A;
     }
  static long sum(int A[]) {
  	long sum=0;
  	for(int i : A) {
  		sum+=i;
  	}
  	return sum;
  }
  static long sum(long A[]) {
  	long sum=0;
  	for(long i : A) {
  		sum+=i;
  	}
  	return sum;
  }
  static void reverse(long A[]) {
  	int n=A.length;
  	long B[]=new long[n];
  	for(int i=0;i<n;i++) {
  		B[i]=A[n-i-1];
  	}
  	for(int i=0;i<n;i++)
  		A[i]=B[i];
  	
  }
  static void reverse(int A[]) {
  	int n=A.length;
  	int B[]=new int[n];
  	for(int i=0;i<n;i++) {
  		B[i]=A[n-i-1];
  	}
  	for(int i=0;i<n;i++)
  		A[i]=B[i];
  	
  }
  static void input(int A[],int B[]) {
  	   for(int i=0;i<A.length;i++) {
  		   A[i]=sc.nextInt();
  		   B[i]=sc.nextInt();
  	   }
  }
  static int[][] input(int n,int m){
  	int A[][]=new int[n][m];
  	for(int i=0;i<n;i++) {
  		for(int j=0;j<m;j++) {
  			A[i][j]=i();
  		}
  	}
  	return A;
  }
  static char[][] charinput(int n,int m){
  	char A[][]=new char[n][m];
  	for(int i=0;i<n;i++) {
  		String s=s();
  		for(int j=0;j<m;j++) {
  			A[i][j]=s.charAt(j);
  		}
  	}
  	return A;
  }
  static int nextPowerOf2(int n)
  {
      n--;
      n |= n >> 1;
      n |= n >> 2;
      n |= n >> 4;
      n |= n >> 8;
      n |= n >> 16;
      n++;
       
      return n;
  }
  static int highestPowerof2(int x)
  {
     
      x |= x >> 1;
      x |= x >> 2;
      x |= x >> 4;
      x |= x >> 8;
      x |= x >> 16;
       
      return x ^ (x >> 1); 
   
  }
  static long highestPowerof2(long x)
  {
     
      x |= x >> 1;
      x |= x >> 2;
      x |= x >> 4;
      x |= x >> 8;
      x |= x >> 16;
      return x ^ (x >> 1); 
   
  }
  
  static int max(int A[]) {
  	int max=Integer.MIN_VALUE;
  	for(int i=0;i<A.length;i++) {
  		max=Math.max(max, A[i]);
  	}
  	return max;
  }
  static int min(int A[]) {
  	int min=Integer.MAX_VALUE;
  	for(int i=0;i<A.length;i++) {
  		min=Math.min(min, A[i]);
  	}
  	return min;
  }
  static long max(long A[]) {
  	long max=Long.MIN_VALUE;
  	for(int i=0;i<A.length;i++) {
  		max=Math.max(max, A[i]);
  	}
  	return max;
  }
  static long min(long A[]) {
  	long min=Long.MAX_VALUE;
  	for(int i=0;i<A.length;i++) {
  		min=Math.min(min, A[i]);
  	}
  	return min;
  }
  static long [] prefix(long A[]) {
  	long p[]=new long[A.length];
  	p[0]=A[0];
  	for(int i=1;i<A.length;i++)
  		p[i]=p[i-1]+A[i];
  	return p;
  }
  static long [] prefix(int A[]) {
  	long p[]=new long[A.length];
  	p[0]=A[0];
  	for(int i=1;i<A.length;i++)
  		p[i]=p[i-1]+A[i];
  	return p;
  }
  static long [] suffix(long A[]) {
  	long p[]=new long[A.length];
  	p[A.length-1]=A[A.length-1];
  	for(int i=A.length-2;i>=0;i--)
  		p[i]=p[i+1]+A[i];
  	return p;
  }
  static long [] suffix(int A[]) {
  	long p[]=new long[A.length];
  	p[A.length-1]=A[A.length-1];
  	for(int i=A.length-2;i>=0;i--)
  		p[i]=p[i+1]+A[i];
  	return p;
  }
  static void fill(int dp[]) {
  	Arrays.fill(dp, -1);
  }
  static void fill(int dp[][]) {
  	for(int i=0;i<dp.length;i++)
  	Arrays.fill(dp[i], -1);
  }
  static void fill(int dp[][][]) {
  	for(int i=0;i<dp.length;i++) {
  		for(int j=0;j<dp[0].length;j++) {
  			Arrays.fill(dp[i][j],-1);
  		}
  	}
  }
  static void fill(int dp[][][][]) {
  	for(int i=0;i<dp.length;i++) {
  		for(int j=0;j<dp[0].length;j++) {
  			for(int k=0;k<dp[0][0].length;k++) {
  			Arrays.fill(dp[i][j][k],-1);
  			}
  		}
  	}
  }
  static void fill(long dp[]) {
  	Arrays.fill(dp, -1);
  }
  static void fill(long dp[][]) {
  	for(int i=0;i<dp.length;i++)
  	Arrays.fill(dp[i], -1);
  }
  static void fill(long dp[][][]) {
  	for(int i=0;i<dp.length;i++) {
  		for(int j=0;j<dp[0].length;j++) {
  			Arrays.fill(dp[i][j],-1);
  		}
  	}
  }
  static void fill(long dp[][][][]) {
  	for(int i=0;i<dp.length;i++) {
  		for(int j=0;j<dp[0].length;j++) {
  			for(int k=0;k<dp[0][0].length;k++) {
  			Arrays.fill(dp[i][j][k],-1);
  			}
  		}
  	}
  }
  static int min(int a,int b) {
  	return Math.min(a, b);
  }
  static int min(int a,int b,int c) {
  	return Math.min(a, Math.min(b, c));
  }
  static int min(int a,int b,int c,int d) {
  	return Math.min(a, Math.min(b, Math.min(c, d)));
  }
  static int max(int a,int b) {
  	return Math.max(a, b);
  }
  static int max(int a,int b,int c) {
  	return Math.max(a, Math.max(b, c));
  }
  static int max(int a,int b,int c,int d) {
  	return Math.max(a, Math.max(b, Math.max(c, d)));
  }
  static long min(long a,long b) {
  	return Math.min(a, b);
  }
  static long min(long a,long b,long c) {
  	return Math.min(a, Math.min(b, c));
  }
  static long min(long a,long b,long c,long d) {
  	return Math.min(a, Math.min(b, Math.min(c, d)));
  }
  static long max(long a,long b) {
  	return Math.max(a, b);
  }
  static long max(long a,long b,long c) {
  	return Math.max(a, Math.max(b, c));
  }
  static long max(long a,long b,long c,long d) {
  	return Math.max(a, Math.max(b, Math.max(c, d)));
  }
  
  static long power(long x, long y, long p)
  {
  
  	if(y==0)
  		return 1;
  	if(x==0)
  		return 0;
      long res = 1;
      x = x % p;
  
      while (y > 0) {
  
          if (y % 2 == 1)
              res = (res * x) % p;
  
          y = y >> 1; 
          x = (x * x) % p;
      }
  
      return res;
  }
  static long power(long x, long y)
  {
  
  	if(y==0)
  		return 1;
  	if(x==0)
  		return 0;
      long res = 1;
  
      while (y > 0) {
  
          if (y % 2 == 1)
              res = (res * x);
  
          y = y >> 1; 
          x = (x * x);
      }
  
      return res;
  }
  static void print(int A[]) {
  	for(int i : A) {
  		System.out.print(i+" ");
  	}
  	System.out.println();
  }
  static void print(long A[]) {
  	for(long i : A) {
  		System.out.print(i+" ");
  	}
  	System.out.println();
  }
  static long mod(long x) {
  	  return ((x%mod + mod)%mod);
  }
  static String reverse(String s) {
  	StringBuffer p=new StringBuffer(s);
  	p.reverse();
  	return p.toString();
  }
  
       static int i() {
      	 return sc.nextInt();
       }
       static String s() {
      	 return sc.next();
       }
       static long l() {
      	 return sc.nextLong();
       }  
       static void sort(int[] A){
          int n = A.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i){
              int tmp = A[i];
              int randomPos = i + rnd.nextInt(n-i);
              A[i] = A[randomPos];
              A[randomPos] = tmp;
          }
          Arrays.sort(A);
       }
       static void sort(long[] A){
  	        int n = A.length;
  	        Random rnd = new Random();
  	        for(int i=0; i<n; ++i){
  	            long tmp = A[i];
  	            int randomPos = i + rnd.nextInt(n-i);
  	            A[i] = A[randomPos];
  	            A[randomPos] = tmp;
  	        }
  	        Arrays.sort(A);
  	     }
    static String sort(String s) {
   	 Character ch[]=new Character[s.length()];
   	 for(int i=0;i<s.length();i++) {
   		 ch[i]=s.charAt(i);
   	 }
   	 Arrays.sort(ch);
   	 StringBuffer st=new StringBuffer("");
   	 for(int i=0;i<s.length();i++) {
   		 st.append(ch[i]);
   	 }
   	 return st.toString();
    }
    static HashMap<Integer,Integer> hash(int A[]){
  	  HashMap<Integer,Integer> map=new HashMap<Integer, Integer>();
  	  for(int i : A) {
  		  if(map.containsKey(i)) {
  			  map.put(i, map.get(i)+1);
  		  }
  		  else {
  			  map.put(i, 1);
  		  }
  	  }
  	  return map;
    }
    static HashMap<Long,Integer> hash(long A[]){
  	  HashMap<Long,Integer> map=new HashMap<Long, Integer>();
  	  for(long i : A) {
  		  if(map.containsKey(i)) {
  			  map.put(i, map.get(i)+1);
  		  }
  		  else {
  			  map.put(i, 1);
  		  }
  	  }
  	  return map;
    }
    static TreeMap<Integer,Integer> tree(int A[]){
  	  TreeMap<Integer,Integer> map=new TreeMap<Integer, Integer>();
  	  for(int i : A) {
  		  if(map.containsKey(i)) {
  			  map.put(i, map.get(i)+1);
  		  }
  		  else {
  			  map.put(i, 1);
  		  }
  	  }
  	  return map;
    }
    static TreeMap<Long,Integer> tree(long A[]){
  	  TreeMap<Long,Integer> map=new TreeMap<Long, Integer>();
  	  for(long i : A) {
  		  if(map.containsKey(i)) {
  			  map.put(i, map.get(i)+1);
  		  }
  		  else {
  			  map.put(i, 1);
  		  }
  	  }
  	  return map;
    }
       static boolean prime(int n) 
  	    { 
  	        if (n <= 1) 
  	            return false; 
  	        if (n <= 3) 
  	            return true; 
  	        if (n % 2 == 0 || n % 3 == 0) 
  	            return false; 
  	        double sq=Math.sqrt(n);
  	  
  	        for (int i = 5; i <= sq; i = i + 6) 
  	            if (n % i == 0 || n % (i + 2) == 0) 
  	                return false; 
  	        return true; 
  	    } 
       static boolean prime(long n) 
  	    { 
  	        if (n <= 1) 
  	            return false; 
  	        if (n <= 3) 
  	            return true; 
  	        if (n % 2 == 0 || n % 3 == 0) 
  	            return false; 
  	        double sq=Math.sqrt(n);
  	  
  	        for (int i = 5; i <= sq; i = i + 6) 
  	            if (n % i == 0 || n % (i + 2) == 0) 
  	                return false; 
  	        return true; 
  	    } 
       static int gcd(int a, int b) 
       { 
           if (a == 0) 
               return b; 
           return gcd(b % a, a); 
       } 
       static long gcd(long a, long b) 
       { 
           if (a == 0) 
               return b; 
           return gcd(b % a, a); 
       } 
       
          
      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; 
          } 
      } 
  } 
  
  
  
  