diff --git a/12.rkt b/12.rkt
new file mode 100644
index 0000000..3523370
--- /dev/null
+++ b/12.rkt
@@ -0,0 +1,61 @@
+#lang curly-fn racket
+
+(require "scripts/aoc.rkt")
+
+;; solution for day 12
+
+(define (grid-h grid) (vector-length grid))
+(define (grid-w grid) (vector-length (vector-ref grid 0)))
+(define (grid-ref grid y x) (vector-ref (vector-ref grid y) x))
+(define (grid-find grid c)
+  (for*/first ([y (in-range (grid-h grid))] [x (in-range (grid-w grid))]
+               #:when (eq? c (grid-ref grid y x)))
+    (cons x y)))
+
+(define (part1 input)
+  (match-define (list grid G) input)
+  (define-values [a b] (dijkstra G (grid-find grid #\E)))
+  (hash-ref a (grid-find grid #\S)))
+
+(define (part2 input)
+  (match-define (list grid G) input)
+  (define-values [a b] (dijkstra G (grid-find grid #\E)))
+  (apply min
+    (for*/list ([y (in-range (grid-h grid))]
+                [x (in-range (grid-w grid))]
+                #:when (eq? (grid-ref grid y x) #\a)
+                [dist (in-value (hash-ref a (cons x y)))]
+                #:unless (= +inf.0 dist))
+      dist)))
+
+(define (parse fname)
+  (define grid (for/vector ([line (in-list (file->lines fname))])
+                  (list->vector (string->list line))))
+
+  (define (valid-move? a b)
+    (define (hm->int x)
+      (char->integer (match x [#\S #\a] [#\E #\z] [_ x])))
+    (<= (hm->int b) (add1 (hm->int a))))
+
+  (define edges
+    (for*/fold ([edges '()])
+               ([y (in-range (grid-h grid))] [x (in-range (grid-w grid))]
+                [neigh (in-list (list (cons (add1 x) y)
+                                      (cons (sub1 x) y)
+                                      (cons x (add1 y))
+                                      (cons x (sub1 y))))]
+                #:when (< -1 (car neigh) (grid-w grid))
+                #:when (< -1 (cdr neigh) (grid-h grid)))
+      (define this-val (grid-ref grid y x))
+      (define neigh-val (grid-ref grid (cdr neigh) (car neigh)))
+      (if (valid-move? this-val neigh-val)
+        (cons (list neigh (cons x y)) edges)
+        edges)))
+
+  (list grid (directed-graph edges)))
+
+(module+ main
+  (define input (parse "inputs/12"))
+  (answer 12 1 (time (part1 input)))
+  (answer 12 2 (time (part2 input)))
+  (displayln "meow"))
diff --git a/inputs/12 b/inputs/12
new file mode 100644
index 0000000..bb083e9
--- /dev/null
+++ b/inputs/12
@@ -0,0 +1,41 @@
+abaaaaaccccccccccccccccccaaaaaaaaaaaaaccccaaaaaaaccccccccccccccccccccccccccccaaaaaa
+abaaaaaaccaaaacccccccccccaaaaaaaaacaaaacaaaaaaaaaacccccccccccccccccccccccccccaaaaaa
+abaaaaaacaaaaaccccccccccaaaaaaaaaaaaaaacaaaaaaaaaacccccccccccccaacccccccccccccaaaaa
+abaaaaaacaaaaaacccccccccaaaaaaaaaaaaaaccaaacaaaccccccccccccccccaacccccccccccccccaaa
+abccaaaccaaaaaacccaaaaccaaaaaaaaaaaaaccccaacaaacccccccccaacaccccacccccccccccccccaaa
+abcccccccaaaaaccccaaaacccccaaaaacccaaaccaaaaaaccccccccccaaaaccccccccccccccccccccaac
+abcccccccccaaaccccaaaacccccaaaaacccccccccaaaaaccccccccccklllllccccccccccccccccccccc
+abcccccccccccccccccaaccccccccaaccccccccaaaaaaaccccccccckklllllllcccccddccccaacccccc
+abaccccccccccccccccccccccccccaaccccccccaaaaaaaaccccccckkkklslllllcccddddddaaacccccc
+abacccccccccccccccccccccccccccccccaaaccaaaaaaaaccccccckkkssssslllllcddddddddacccccc
+abaccccccccccccccccccccccccccccccccaaaaccaaacaccccccckkksssssssslllmmmmmdddddaacccc
+abcccccccccccccccaaacccccccccccccaaaaaaccaacccccccccckkkssssusssslmmmmmmmdddddacccc
+abcccccccaaccccaaaaacccccccccccccaaaaaccccccaaaaaccckkkrssuuuussssqmmmmmmmmdddccccc
+abcccccccaaccccaaaaaacccccccaaccccaaaaacccccaaaaacckkkkrruuuuuussqqqqqqmmmmdddccccc
+abccccaaaaaaaacaaaaaacccccccaaaaccaaccaccccaaaaaacjkkkrrruuuxuuusqqqqqqqmmmmeeccccc
+abcaaaaaaaaaaacaaaaaccccccaaaaaacccccaaccccaaaaajjjjrrrrruuuxxuvvvvvvvqqqmmmeeccccc
+abcaacccaaaaccccaaaaaaacccaaaaacccacaaaccccaaaajjjjrrrrruuuxxxxvvvvvvvqqqmmeeeccccc
+abaaaaccaaaaacccccccaaaccccaaaaacaaaaaaaacccaajjjjrrrrtuuuuxxxyvyyyvvvqqqnneeeccccc
+abaaaaaaaaaaacccaaaaaaaccccaacaacaaaaaaaacccccjjjrrrttttuxxxxxyyyyyvvvqqnnneeeccccc
+abaaaaaaaccaacccaaaaaaaaacccccccccaaaaaaccccccjjjrrrtttxxxxxxxyyyyyvvvqqnnneeeccccc
+SbaaaaaacccccccccaaaaaaaaaccccccccaaaaacccccccjjjrrrtttxxxEzzzzyyyvvrrrnnneeecccccc
+abaaaaacccccccccccaaaaaaacccccccccaaaaaaccccccjjjqqqtttxxxxxyyyyyvvvrrrnnneeecccccc
+abaaacccccccccccaaaaaaaccaaccccccccccaaccaaaaajjjqqqttttxxxxyyyyyyvvrrrnnneeecccccc
+abaaacccccccccccaaaaaaaccaaacaaacccccccccaaaaajjjjqqqtttttxxyywyyyywvrrnnnfeecccccc
+abcaaacccccccaaaaaaaaaaacaaaaaaaccccccccaaaaaaciiiiqqqqtttxwyywwyywwwrrrnnfffcccccc
+abcccccccccccaaaaaaaaaaccaaaaaacccccccccaaaaaacciiiiqqqqttwwywwwwwwwwrrrnnfffcccccc
+abccccccccccccaaaaaacccaaaaaaaacccccccccaaaaaaccciiiiqqqttwwwwwswwwwrrrrnnfffcccccc
+abccccccccccccaaaaaacccaaaaaaaaacccccccccaaacccccciiiqqqtswwwwssssrrrrrroofffcccccc
+abccccccaaaaacaaaaaacccaaaaaaaaaaccccccccccccccccciiiqqqssswsssssssrrrrooofffaccccc
+abccccccaaaaacaaccaaccccccaaacaaacccccccccccccccccciiiqqssssssspoorrrooooofffaacccc
+abcccccaaaaaacccccccccccccaaacccccccccccccccccccccciiiqppssssspppooooooooffffaacccc
+abcccccaaaaaacccccccccccccaacccccccccccccccccccccccciipppppppppppoooooooffffaaccccc
+abcccccaaaaaaccccccccccccccccccccccccccccccccccccccciihppppppppgggggggggfffaaaccccc
+abccccccaaacccccccccccccccccccccccaccccccccccccccccchhhhpppppphggggggggggfaaaaccccc
+abaaaccccccccccccccccccccccaccccaaacccccccccccccccccchhhhhhhhhhgggggggggcaacccccccc
+abaaccaaaccaccccccccccccccaaacccaaacaacccaaaaacccccccchhhhhhhhhgaaccccccccccccccccc
+abaaacaaacaacccccccccaaaccaaaacaaaaaaaaccaaaaaccccccccchhhhhhaaaaacccccccccccccccca
+abaaaccaaaaaccccccccccaaacaaaaaaaacaaaaccaaaaaaccccccccccaaacccaaaacccccccccccaccca
+abcccaaaaaaccccccccccaaaaaaaaaaaaacaaaaccaaaaaaccccccccccaaaccccaaaccccccccccaaaaaa
+abcccaaaaaaaacccccccaaaaaaaaaaaaaaaaaccccaaaaaacccccccccccccccccccccccccccccccaaaaa
+abcccaacaaaaaccccccaaaaaaaaaaaaaaaaaaacccccaacccccccccccccccccccccccccccccccccaaaaa
diff --git a/inputs/12-test1 b/inputs/12-test1
new file mode 100644
index 0000000..86e9cac
--- /dev/null
+++ b/inputs/12-test1
@@ -0,0 +1,5 @@
+Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi