(defconstant +mod+ 998244353)

(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((n (read))
         (a (read))
         (b (read))
         (fact-table (make-array (1+ n))))
    (setf (aref fact-table 0) 1)
    (loop for i from 1 to n
          do (setf (aref fact-table i) (mod (* i (aref fact-table (1- i))) +mod+)))
    (format t "~d~%" (if (= a b)
                         (- (aref fact-table n) (* 2 (aref fact-table (1- n))))
                         (mod (- (+ (aref fact-table n) (aref fact-table (- n 2))) (* 2 (aref fact-table (1- n)))) +mod+)))))

(main)