my_world

#include <iostream>

class Node
{
public:
	int data;
	Node *next;
	Node(int data)
	{
		this->data = data;
		this->next = NULL;
	}
};

using namespace std;


Node *takeinput()
{
	int data;
	cin >> data;
	Node *head = NULL, *tail = NULL;
	while (data != -1)
	{
		Node *newnode = new Node(data);
		if (head == NULL)
		{
			head = newnode;
			tail = newnode;
		}
		else
		{
			tail->next = newnode;
			tail = newnode;
		}
		cin >> data;
	}
	return head;
}

void print(Node *head)
{
	Node *temp = head;
	while (temp != NULL)
	{
		cout << temp->data << " ";
		temp = temp->next;
	}
	cout << endl;
}
*Node *removeDuplicates(Node *head){
Node* temp=head;
    
    while(temp!=NULL){
        Node*temp1=temp->next;
        while(temp->data==temp1->data){
                         temp1=temp1->next;
                   }
        if(temp1!=temp->next){
            temp->next=temp1;
            }
        temp=temp1;
        }
     return head;
}
int main()
{
	int t;
	cin >> t;
	while (t--)
	{
		Node *head = takeinput();
		head = removeDuplicates(head);
		print(head);
	}
	return 0;
}