description: Monocarp is the coach of the Berland State University programming teams. He decided to compose a problemset for a training session for his teams.
  
  Monocarp has n problems that none of his students have seen yet. The i-th problem has a topic a_i (an integer from 1 to n) and a difficulty b_i (an integer from 1 to n). All problems are different, that is, there are no two tasks that have the same topic and difficulty at the same time.
  
  Monocarp decided to select exactly 3 problems from n problems for the problemset. The problems should satisfy at least one of two conditions (possibly, both):
  
    * the topics of all three selected problems are different; 
    * the difficulties of all three selected problems are different. 
  
  
  
  Your task is to determine the number of ways to select three problems for the problemset.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 50000) — the number of testcases.
  
  The first line of each testcase contains an integer n (3 ≤ n ≤ 2 ⋅ 10^5) — the number of problems that Monocarp have.
  
  In the i-th of the following n lines, there are two integers a_i and b_i (1 ≤ a_i, b_i ≤ n) — the topic and the difficulty of the i-th problem.
  
  It is guaranteed that there are no two problems that have the same topic and difficulty at the same time.
  
  The sum of n over all testcases doesn't exceed 2 ⋅ 10^5.
  
  Output
  
  Print the number of ways to select three training problems that meet either of the requirements described in the statement.
  
  Example
  
  Input
  
  
  2
  4
  2 4
  3 4
  2 1
  1 3
  5
  1 5
  2 4
  3 3
  4 2
  5 1
  
  
  Output
  
  
  3
  10
  
  Note
  
  In the first example, you can take the following sets of three problems:
  
    * problems 1, 2, 4; 
    * problems 1, 3, 4; 
    * problems 2, 3, 4. 
  
  
  
  Thus, the number of ways is equal to three.
solution: import java.io.*;
  import java.util.*;
  public class Main {
      public static void main(String[] args) {
          FastReader input=new FastReader();
          PrintWriter out=new PrintWriter(System.out);
          int T=input.nextInt();
          while(T-->0)
          {
              int n=input.nextInt();
              int a[][]=new int[n][2];
              int top[]=new int[n+1];
              int bottom[]=new int[n+1];
              ArrayList<Integer> arr[]=new ArrayList[n+1];
              for(int i=1;i<=n;i++) arr[i]=new ArrayList<>();
              for(int i=0;i<n;i++)
              {
                  a[i][0]=input.nextInt();
                  a[i][1]=input.nextInt();
                  top[a[i][0]]++;
                  bottom[a[i][1]]++;
                  arr[a[i][0]].add(a[i][1]);
              }
              long t=0;
              for(int i=1;i<=n;i++)
              {
                  long s=0;
                  for(int j=0;j<arr[i].size();j++)
                  {
                      int v=arr[i].get(j);
                      long sum=(long)(arr[i].size()-1)*(long)(bottom[v]-1);
                      s+=sum;
                  }
                  t+=s;
              }
              long total=(long)n*(long)(n-1)*(long)(n-2)/6;
              System.out.println(total-t);
          }
          out.close();
      }
      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;
          }
      }
  }