(defconstant +mod107+ 1000000007)

(defun %mod-mat-mul (n a b m)
  (let ((res (make-array `(,n ,n) :initial-element 0)))
    (dotimes (i n)
      (dotimes (j n)
        (dotimes (k n)
          (incf (aref res i j) (* (aref a i k) (aref b k j)))
          (setf (aref res i j) (mod (aref res i j) m)))))
    res))

(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((a (read))
         (b (read))
         (n (read))
         (A (make-array '(2 2) :initial-contents `((,a ,b) (1 0))))
         (E (make-array '(2 2) :initial-contents `((1 0) (0 1))))
         (m (1- n)))
    (when (<= n 1)
          (format t "~d~%" n)
          (return-from main))
    (dotimes (i 30)
      (unless (zerop (logand 1 (ash m (- i))))
              (setf E (%mod-mat-mul 2 A E +mod107+)))
      (setf A (%mod-mat-mul 2 A A +mod107+)))
    (format t "~d~%" (aref E 0 0))))

(main)