diff --git a/p12/p12.org b/p12/p12.org
index 2a481cc..c4c30c0 100644
--- a/p12/p12.org
+++ b/p12/p12.org
@@ -49,41 +49,64 @@ and split into a list of list of chars
 #+end_src
 
 collect all plants type and return a list of list of positions
+#+begin_src emacs-lisp :results none
+  (setq plants (-distinct (-mapcat #'identity data-chars)))
+
+  (setq groups (-map (lambda (pl)
+		       (-map #'cadr
+			      (--filter (eq (car it) pl)
+					(-mapcat #'identity
+						  (-map-indexed (lambda (y l) (-map-indexed (lambda (x el) (list el (list x y))) l)) data-chars)))))
+		     plants))
+#+end_src
+
 
 now we need to split each group into regions
-ACC is a list of regions. The function  
-#+begin_src emacs-lisp :results none
-  (defun agglomerate (acc el)
-    (let ((nbhs (acceptable-neighbours el)))
-      (cons (-mapcat #'identity (cons (list el) (--filter (-intersection it nbhs) acc))) 
-	    (--filter (not (-intersection it nbhs)) acc))
+  ACC is a list of regions. The function  
+ #+begin_src emacs-lisp :results none
+    (defun agglomerate (acc el)
+      (let ((nbhs (acceptable-neighbours el)))
+	(cons (-mapcat #'identity (cons (list el) (--filter (-intersection it nbhs) acc))) 
+	      (--filter (not (-intersection it nbhs)) acc))
+	)
       )
-    )
 
-  (setq regions (--mapcat (-reduce-from #'agglomerate nil it) groups))
+    (setq regions (--mapcat (-reduce-from #'agglomerate nil it) groups))
 #+end_src
 
 #+begin_src emacs-lisp
-    (defun count-fence (el)
-      (let ((i (plant el))
-	    (pos el))
-	(length (--filter (not (eq i it)) (-map #'plant (neighbours pos))))))
+  (defun count-fence (el)
+    (let ((i (plant el))
+	  (pos el))
+      (length (--filter (not (eq i it)) (-map #'plant (neighbours pos))))))
+
+  (defun vertex-p (el dir)
+    (let* ((x (car el))
+	   (y (cadr el))
+	   (a (car dir))
+	   (b (cadr dir))
+	   (opposite (list (+ x a) (+ y b)))
+	   (adjh (list (+ x a) y))
+	   (adjv (list x (+ y b))))
+      (or (and (not (eq (plant el) (plant adjh)))
+	       (not (eq (plant el) (plant adjv))))
+	  (and (eq (plant el) (plant adjh))
+	       (eq (plant el) (plant adjv))
+	       (not (eq (plant el) (plant opposite))))))
+    )
+  (defun count-vertices (el)
+    (length (-non-nil (--map (vertex-p el it) '((1 1) (1 -1) (-1 1) (-1 -1)))))
+    )
 
-    (defun count-vertices (el)
-      
-      )
   (-reduce #'+  (--map (* (car it) (cdr it))
 		       (-zip-pair (-map #'length regions)
 				  (-map (lambda (region) (-reduce #'+ (-map #'count-fence region))) regions))))
-#+end_src
-
-#+RESULTS:
-: 1451030
-
 
-#+begin_src emacs-lisp :no-results
-  (setq areas (-frequencies (-mapcat #'identity data-chars)))
+    (-reduce #'+  (--map (* (car it) (cdr it))
+		       (-zip-pair (-map #'length regions)
+				  (-map (lambda (region) (-reduce #'+ (-map #'count-vertices region))) regions))))
 #+end_src
 
+#+RESULTS:
+: 859494
 
-(plant ' (0 9))