#include <stdio.h>
#include <stdlib.h>

typedef struct Node {
  int data;
  struct Node *next;
} Node;

Node *appendNode(Node *n) {
  int data;
  scanf("%d", &data);
  Node *node = malloc(sizeof(struct Node));
  node->data = data;
  node->next = NULL;
  n->next = node;
  return node;
}

Node *makeList(int col) {
  Node *head, *ptr;
  head = malloc(sizeof(Node));
  head->next = NULL;

  ptr = head;
  for (int i = 0; i < col; i++) {
    ptr = appendNode(ptr);
  }
  return head;
}

void delete(Node *head) {
	if (head->next == NULL) {
		free(head);
	} else {
		delete(head->next);
	}
}

int main(void) {
  int rows;
  int col;
  int count;
  scanf("%d", &rows);
  Node *ptr;

  for (int i = 0; i < rows; i++) {
    scanf("%d", &col);
    Node *head = makeList(col);

    count = 0;
    for (ptr = head->next; ptr != NULL; ptr = ptr->next) {
      if (count % 2 == 1) {
        if (count == 1) {
          printf("%d", ptr->data);
        } else {
          printf(" %d", ptr->data);
        }
      }
      count++;
    }
    printf("\n");

		delete(head);
  }

  return 0;
}