(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((dp (make-array (list 14 14) :element-type 'integer :initial-element 0))
         (n (read)))
    (setf (aref dp 0 0) 1)
    (loop for i from 1 to n do
          (loop for j to n do
                (if (>= j i)
                    (setf (aref dp i j) (+ (aref dp i (1- j)) (aref dp (1- i) j)))
                    (setf (aref dp i j) (aref dp (1- i) j)))))
    (format t "~d~%" (aref dp n n))))