WA in FIRESC

Hello, everyone. I have a problem with the FIRESC. Can you tell me what is wrong with my code? It would be also nice if you can provide some test cases that might be a tricky. Thanks in advance.

import java.util.*;

public class Main {
  
  static int[] employee;
  
  public static void main(String[] args) {

    Scanner read = new Scanner(System.in);
    int t = read.nextInt();

    while(t-- > 0) {
     
      int n = read.nextInt();
      int m = read.nextInt();
      
      employee = new int[n];      
      for(int i=0; i<n; i++) {
        
        employee[i] = i;
        
      }
      
      WeightQuickUnion qUnion = new WeightQuickUnion(employee);
      
      //Relation between employee
      for(int i=0; i<m; i++) {
     
        int a = read.nextInt();
        int b = read.nextInt();        
        
        if(!qUnion.isConnect(a-1, b-1))
          qUnion.union(a-1,b-1);
        
      }
      qUnion.findRoot();
      System.out.println(qUnion.getWay() + " " + qUnion.getLeader());
      
    }

  }
  
}

class WeightQuickUnion {
  
  private int[] id;
  private int[] sz;
  private List<Integer> root = new ArrayList<Integer>();
  
  public WeightQuickUnion(int[] id) {
    
    this.id = id;
    sz = new int[id.length];

    for(int i=0; i<id.length; i++) {   
      
      id[i]=i;
      sz[i]++;
      
    }
      
   
  }
  
  public int root(int i) {
    
    while(i != id[i]) {
      
      id[i] = id[id[i]];
      i = id[i];
      
    }
    
    return i;
    
  }
  
  public void union(int p, int q) {
    
    int i = root(p);
    int j = root(q);
    
    if(sz[i] > sz[j]) {
      
      id[j] = i;
      sz[i] += sz[j];
      
    }
    else {
      
      id[i] = j;
      sz[j] += sz[i];
      
    }
    
  }
  
  public boolean isConnect(int p, int q) {
    
    return root(p)==root(q);
    
  }
  
  public long getLeader() {
    
    long temp = 1;
    
    for(int i=0; i<root.size(); i++) {
      
      temp *= sz[root.get(i)];
    
    }
    
    return temp;
    
  }
  
  public void findRoot() {
    
    for(int i=0; i<id.length; i++) {
      
      if(id[i] == i) {
        root.add(i);
      }
    }
    
  }
  
  public int getWay() {
    
    return root.size();
    
  }
  
}
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