(defun read-int ()
  (parse-integer (read-line)))

(defun solve ()
  (let ((T (read-int)))
    (dotimes (i T)
      (let* ((N (read-int))
             (half-N (floor N 2))
             (s (concatenate 'string
                             (make-string half-N :initial-element #\a)
                             (make-string (- N half-N) :initial-element #\b))))
        (format t "~a~%" s)))))
        
(solve)