public static void main(String[] argv) {
    node_t<Integer> head = null;

    if (argv.length > 1) {
      //Input the node's value in reverse order.
      for (int i = 0; i < argv.length; i++) {
        node_t<Integer> curr =
            new node_t<Integer>(Integer.parseInt(argv[i]), head);
        head = curr;
      }
      System.out.println(((is_linked_list_a_palindrome(head)) ? "Yes" : "No"));
    } else {
      // A link list is a palindrome.
      for (int i = 6; i >= 1; --i) {
        node_t<Integer> curr =
            new node_t<Integer>(1, head);
        head = curr;
      }
      assert(is_linked_list_a_palindrome(head) == true);

      // Still a palindrome linked list.
      head = null;
      for (int i = 5; i >= 1; --i) {
        node_t<Integer> curr =
            new node_t<Integer>(1, head);
        head = curr;
      }
      head.next.next.data = 3;
      assert(is_linked_list_a_palindrome(head) == true);
      // Not a palindrome linked list.
      head = null;
      for (int i = 5; i >= 1; --i) {
        node_t<Integer> curr =
            new node_t<Integer>(i, head);
        head = curr;
      }
      assert(is_linked_list_a_palindrome(head) == false);
    }
  }