(defun nowroot (s)
    (let ((result 1) (i 0))
    (loop while (< i (length s)) do 
    (if (char= (char s i) #\L)
    (setf result (* result 2)) (setf result (1+ (* result 2))))
    (incf i))
    result)
)

(defun main () (let ((S (read-line))) (format t "~A~%" (nowroot S))))

(main)