description: A rectangle with its opposite corners in (0, 0) and (w, h) and sides parallel to the axes is drawn on a plane.
  
  You are given a list of lattice points such that each point lies on a side of a rectangle but not in its corner. Also, there are at least two points on every side of a rectangle.
  
  Your task is to choose three points in such a way that: 
  
    * exactly two of them belong to the same side of a rectangle; 
    * the area of a triangle formed by them is maximum possible. 
  
  
  
  Print the doubled area of this triangle. It can be shown that the doubled area of any triangle formed by lattice points is always an integer.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of testcases.
  
  The first line of each testcase contains two integers w and h (3 ≤ w, h ≤ 10^6) — the coordinates of the corner of a rectangle.
  
  The next two lines contain the description of the points on two horizontal sides. First, an integer k (2 ≤ k ≤ 2 ⋅ 10^5) — the number of points. Then, k integers x_1 < x_2 < ... < x_k (0 < x_i < w) — the x coordinates of the points in the ascending order. The y coordinate for the first line is 0 and for the second line is h.
  
  The next two lines contain the description of the points on two vertical sides. First, an integer k (2 ≤ k ≤ 2 ⋅ 10^5) — the number of points. Then, k integers y_1 < y_2 < ... < y_k (0 < y_i < h) — the y coordinates of the points in the ascending order. The x coordinate for the first line is 0 and for the second line is w.
  
  The total number of points on all sides in all testcases doesn't exceed 2 ⋅ 10^5.
  
  Output
  
  For each testcase print a single integer — the doubled maximum area of a triangle formed by such three points that exactly two of them belong to the same side.
  
  Example
  
  Input
  
  
  3
  5 8
  2 1 2
  3 2 3 4
  3 1 4 6
  2 4 5
  10 7
  2 3 9
  2 1 7
  3 1 3 4
  3 4 5 6
  11 5
  3 1 6 8
  3 3 6 8
  3 1 3 4
  2 2 4
  
  
  Output
  
  
  25
  42
  35
  
  Note
  
  The points in the first testcase of the example: 
  
    * (1, 0), (2, 0); 
    * (2, 8), (3, 8), (4, 8); 
    * (0, 1), (0, 4), (0, 6); 
    * (5, 4), (5, 5). 
  
  
  
  The largest triangle is formed by points (0, 1), (0, 6) and (5, 4) — its area is 25/2. Thus, the doubled area is 25. Two points that are on the same side are: (0, 1) and (0, 6).
solution: import java.util.*;
  import java.io.*;
  
  public class B {
  
      public void prayGod() throws IOException {
          int t = nextInt();
          while (t-- > 0) {
              long w = nextLong();
              long h = nextLong();
  
              ArrayList<Long> x = new ArrayList<>();
              ArrayList<Long> y = new ArrayList<>();
  
              int sz = nextInt();
              for (int i = 0; i < sz; i++) {
                  x.add(nextLong());
              }
  
              sz = nextInt();
              for (int i = 0; i < sz; i++) {
                  y.add(nextLong());
              }
  
              long sol1 = Math.max(h * (y.get(y.size() - 1) - y.get(0)), h * (x.get(x.size() - 1) - x.get(0)));
  
              x = new ArrayList<>();
              y = new ArrayList<>();
  
              sz = nextInt();
              for (int i = 0; i < sz; i++) {
                  x.add(nextLong());
              }
  
              sz = nextInt();
              for (int i = 0; i < sz; i++) {
                  y.add(nextLong());
              }
  
              long sol2 = Math.max(w * (y.get(y.size() - 1) - y.get(0)), w * (x.get(x.size() - 1) - x.get(0)));
  
              out.println(Math.max(sol1, sol2));
  
          }
      }
  
      public long binpow(int a, int b) {
          if (b < 0)
              return 0;
          long ret = 1, curr = a;
          while (b > 0) {
              if (b % 2 == 1)
                  ret = (ret * curr) % mod;
              b /= 2;
              curr = (curr * curr) % mod;
          }
          return ret;
      }
  
      public void printVerdict(boolean verdict) {
          if (verdict)
              out.println(VERDICT_YES);
          else
              out.println(VERDICT_NO);
      }
  
      static final String VERDICT_YES = "YES";
      static final String VERDICT_NO = "NO";
      static final boolean RUN_TIMING = true;
      static final boolean AUTOFLUSH = false;
      static final boolean FILE_INPUT = false;
      static final boolean FILE_OUTPUT = false;
  
      static int iinf = 0x3f3f3f3f;
      static long inf = (long) 1e18 + 10;
      static long mod = (long) 1e9 + 7;
  
      static char[] inputBuffer = new char[1 << 20];
      static PushbackReader in = new PushbackReader(new BufferedReader(new InputStreamReader(System.in)), 1 << 20);
      static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)), AUTOFLUSH);
  
      // int data-type
      public int nextInt() throws IOException {
          return Integer.parseInt(next());
      }
  
      public int[] nextIntArray(int n) throws IOException {
          int[] arr = new int[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextInt();
          return arr;
      }
  
      public void sort(int[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      public static void printArray(int[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      // long data-type
      public long nextLong() throws IOException {
          return Long.parseLong(next());
      }
  
      public long[] nextLongArray(int n) throws IOException {
          long[] arr = new long[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextLong();
          return arr;
      }
  
      public static void printArray(long[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      public void sort(long[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      // double data-type
      public double nextDouble() throws IOException {
          return Double.parseDouble(next());
      }
  
      public double[] nextDoubleArray(int n) throws IOException {
          double[] arr = new double[n];
          for (int i = 0; i < n; i++)
              arr[i] = nextDouble();
          return arr;
      }
  
      public static void printArray(double[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      // Generic type
      public <T> void sort(T[] a) {
          shuffle(a);
          Arrays.sort(a);
      }
  
      public static <T> void printArray(T[] arr) {
          for (int i = 0; i < arr.length; i++)
              out.print(arr[i] + " ");
          out.println();
      }
  
      public String next() throws IOException {
          int len = 0;
          int c;
          do {
              c = in.read();
          } while (Character.isWhitespace(c) && c != -1);
          if (c == -1) {
              throw new NoSuchElementException("Reached EOF");
          }
          do {
              inputBuffer[len] = (char) c;
              len++;
              c = in.read();
          } while (!Character.isWhitespace(c) && c != -1);
          while (c != '\n' && Character.isWhitespace(c) && c != -1) {
              c = in.read();
          }
          if (c != -1 && c != '\n') {
              in.unread(c);
          }
          return new String(inputBuffer, 0, len);
      }
  
      public String nextLine() throws IOException {
          int len = 0;
          int c;
          while ((c = in.read()) != '\n' && c != -1) {
              if (c == '\r') {
                  continue;
              }
              inputBuffer[len] = (char) c;
              len++;
          }
          return new String(inputBuffer, 0, len);
      }
  
      public boolean hasNext() throws IOException {
          String line = nextLine();
          if (line.isEmpty()) {
              return false;
          }
          in.unread('\n');
          in.unread(line.toCharArray());
          return true;
      }
  
      public void shuffle(int[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              int temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public void shuffle(long[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              long temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public void shuffle(Object[] arr) {
          int n = arr.length;
          for (int i = 0; i < n; i++) {
              int j = (int) (Math.random() * (n - i));
              Object temp = arr[i];
              arr[i] = arr[j];
              arr[j] = temp;
          }
      }
  
      public static void main(String[] args) throws IOException {
          if (FILE_INPUT)
              in = new PushbackReader(new BufferedReader(new FileReader(new File("output.txt"))), 1 << 20);
          if (FILE_OUTPUT)
              out = new PrintWriter(new FileWriter(new File("output.txt")));
  
          long time = 0;
          time -= System.nanoTime();
          new B().prayGod();
          time += System.nanoTime();
  
          if (RUN_TIMING)
              System.err.printf("%.3f ms%n", time / 1000000.0);
  
          out.flush();
          in.close();
      }
  }