content: import java.io.*;
  import java.math.*;
  import java.security.*;
  import java.text.*;
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.regex.*;
  
  public class Solution {
  
      static class SinglyLinkedListNode {
          public int data;
          public SinglyLinkedListNode next;
  
          public SinglyLinkedListNode(int nodeData) {
              this.data = nodeData;
              this.next = null;
          }
      }
  
      static class SinglyLinkedList {
          public SinglyLinkedListNode head;
          public SinglyLinkedListNode tail;
  
          public SinglyLinkedList() {
              this.head = null;
              this.tail = null;
          }
  
          public void insertNode(int nodeData) {
              SinglyLinkedListNode node = new SinglyLinkedListNode(nodeData);
  
              if (this.head == null) {
                  this.head = node;
              } else {
                  this.tail.next = node;
              }
  
              this.tail = node;
          }
      }
  
      public static void printSinglyLinkedList(SinglyLinkedListNode node, String sep, BufferedWriter bufferedWriter) throws IOException {
          while (node != null) {
              bufferedWriter.write(String.valueOf(node.data));
  
              node = node.next;
  
              if (node != null) {
                  bufferedWriter.write(sep);
              }
          }
      }
  
  class Result {
  
      /*
       * Complete the 'removeDuplicates' function below.
       *
       * The function is expected to return an INTEGER_SINGLY_LINKED_LIST.
       * The function accepts INTEGER_SINGLY_LINKED_LIST llist as parameter.
       */
  
      /*
       * For your reference:
       *
       * SinglyLinkedListNode {
       *     int data;
       *     SinglyLinkedListNode next;
       * }
       *
       */
  
      public static SinglyLinkedListNode removeDuplicates(SinglyLinkedListNode llist) {
      // Write your code here
      if (llist == null || llist.next == null) {
          return llist;
      }
      // 2262986
      SinglyLinkedListNode current = llist;
      while (current.next != null) {
          if (current.data == current.next.data) {
              current.next = current.next.next;
          } else {
              current = current.next;
          }
      }
      // 2262986
      return llist;
  
      }
  
  }
  
      private static final Scanner scanner = new Scanner(System.in);
  
      public static void main(String[] args) throws IOException {
          BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
  
          int t = scanner.nextInt();
          scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
  
          for (int tItr = 0; tItr < t; tItr++) {
              SinglyLinkedList llist = new SinglyLinkedList();
  
              int llistCount = scanner.nextInt();
              scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
  
              for (int i = 0; i < llistCount; i++) {
                  int llistItem = scanner.nextInt();
                  scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
  
                  llist.insertNode(llistItem);
              }
  
              SinglyLinkedListNode llist1 = removeDuplicates(llist.head);
  
              printSinglyLinkedList(llist1, " ", bufferedWriter);
              bufferedWriter.newLine();
          }
  
          bufferedWriter.close();
  
          scanner.close();
      }
  }
  