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.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.*;
  
  public class Main {
      public static FastScanners fs = new FastScanners();
  
      public static void main(String[] args) {
          int testCase = 1;
          testCase = fs.nextInt();
          for (int i = 0; i < testCase; i++) {
              solve();
          }
      }
  
      public static void solve() {
          int n = fs.nextInt();
          long ans = 0;
          pair[] pairs = new pair[n];
          Map<Integer, Integer> task = new HashMap<>();
          Map<Integer, Integer> difficulty = new HashMap<>();
          for (int i = 0; i < n; i++) {
              int tsk = fs.nextInt();
              int diff = fs.nextInt();
              task.put(tsk, task.getOrDefault(tsk, 0) + 1);
              difficulty.put(diff, difficulty.getOrDefault(diff, 0) + 1);
              pair p = new pair(tsk, diff);
              pairs[i] = p;
          }
          ans += ((long) n * (n - 1) * (n - 2));
          ans /= 6;
          for (int i = 0; i < n; i++) {
              int currentTask = pairs[i].a;
              int currentDiff = pairs[i].b;
              int similarTaskCount = task.get(currentTask) - 1;
              int similarDiffCount = difficulty.get(currentDiff) - 1;
              ans -= ((long) similarDiffCount * similarTaskCount);
          }
          System.out.println(ans);
      }
  
  }
  
  class pair implements Comparable<pair> {
  
      int a;
      int b;
  
      @Override
      public int compareTo(pair o) {
          return (int) (a - o.a);
      }
  
      public pair(int a, int b) {
  
          this.a = a;
          this.b = b;
  
      }
  
  }
  
  
  class FastScanners {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st = new StringTokenizer("");
  
      String next() {
          while (!st.hasMoreTokens())
              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());
      }
  
  }
  
  