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.util.*;
  import java.io.*;
  
  public class D_Training_Session{
      public static void main(String[] args) {
          FastScanner s= new FastScanner();
        //  PrintWriter out=new PrintWriter(System.out);
          //end of program 
          //out.println(answer);
          //out.close();
          StringBuilder res = new StringBuilder();
          int t=s.nextInt();
          int p=0;
          while(p<t){
          long n=s.nextLong();
          ArrayList<Integer> list1 = new  ArrayList<Integer>();// for type
          HashMap<Integer,ArrayList<Integer>> map1 = new HashMap<Integer,ArrayList<Integer>>();// for type
  
          ArrayList<Integer> list2 = new  ArrayList<Integer>();// for difficulty
          HashMap<Integer,ArrayList<Integer>> map2 = new HashMap<Integer,ArrayList<Integer>>();// for difficulty
        // HashMap<Integer,Integer> map = new  HashMap<Integer,Integer>();
        ArrayList<pair> nice= new  ArrayList<pair>();
          for(int i=0;i<n;i++){
              int a=s.nextInt();
              int b=s.nextInt();
          pair obj5 = new pair(a,b);
          nice.add(obj5);
             if(map1.containsKey(a)){
                map1.get(a).add(b);
             }
             else{
                 ArrayList<Integer> obj = new  ArrayList<Integer>();
                 obj.add(b);
                 map1.put(a,obj);
                 list1.add(a);
  
             }
             if(map2.containsKey(b)){
              map2.get(b).add(a);
           }
           else{
               ArrayList<Integer> obj = new  ArrayList<Integer>();
               obj.add(a);
               map2.put(b,obj);
               list2.add(b);
           }
  
          }
          long sub=0;
          for(int i=0;i<n;i++){
              pair obj = nice.get(i);
              long a=map1.get(obj.a).size()-1;
              long b=map2.get(obj.b).size()-1;
              long c=(a*b);
              sub+=c;
          }
  
          long ans=(n*(n-1)*(n-2))/6;
          ans-=sub;
          res.append(ans+"\n");
          p++;
  
         
      }
      System.out.println(res);
          
  
      }
     
      static class FastScanner {
  		BufferedReader br;
  		StringTokenizer st;
   
  		public FastScanner(String s) {
  			try {
  				br = new BufferedReader(new FileReader(s));
  			} catch (FileNotFoundException e) {
  				// TODO Auto-generated catch block
  				e.printStackTrace();
  			}
  		}
   
  		public FastScanner() {
  			br = new BufferedReader(new InputStreamReader(System.in));
  		}
   
  		String nextToken() {
  			while (st == null || !st.hasMoreElements()) {
  				try {
  					st = new StringTokenizer(br.readLine());
  				} catch (IOException e) {
  					// TODO Auto-generated catch block
  					e.printStackTrace();
  				}
  			}
  			return st.nextToken();
  		}
   
  		int nextInt() {
  			return Integer.parseInt(nextToken());
  		}
   
  		long nextLong() {
  			return Long.parseLong(nextToken());
  		}
   
  		double nextDouble() {
  			return Double.parseDouble(nextToken());
  		}
  	}
  
     static class pair{
         int a;
         int b;
         pair(int c, int d){
             a=c;
             b=d;
         }
     }
  
  
  }