diff --git a/src/2024/day21.lisp b/src/2024/day21.lisp
new file mode 100644
index 0000000..41e6488
--- /dev/null
+++ b/src/2024/day21.lisp
@@ -0,0 +1,42 @@
+
+(defpackage :aoc/2024/21
+  (:use :cl :aoc :alexandria :trivia :lla)
+  (:export
+   #:sample-data
+   #:sample-data2
+   #:part1
+   #:part2
+   ))
+
+(in-package :aoc/2024/21)
+
+
+(defun parse-line (line)
+  line)
+
+
+(defun parse-input (lines)
+  (mapcar #'parse-line lines))
+
+(defparameter input-text (test-input 2024 21))
+(defparameter input-data (parse-input input-text))
+
+(defparameter sample-text (aoc:split-lines ""))
+(defparameter sample-data 
+              (parse-input sample-text))
+
+(defun part1 (data)
+  (length data))
+
+(defun part2 (data)
+  (length data))
+
+(defun solve-day ()
+  (format t "part1: ~A~%" (part1 input-data))
+  (format t "part2: ~A~%" (part2 input-data)))
+
+(defun submit ()
+  (let ((p1 (part1 input-data))
+        (p2 (part2 input-data)))
+    (if p1 (submit-part1 2024 21 p1))
+    (if p2 (submit-part2 2024 21 p2))))
diff --git a/tests/2024/day21-test.lisp b/tests/2024/day21-test.lisp
new file mode 100644
index 0000000..06bab9f
--- /dev/null
+++ b/tests/2024/day21-test.lisp
@@ -0,0 +1,27 @@
+(defpackage :aoc/2024/21/tests
+            (:use :cl :aoc :aoc/tests :aoc/2024/tests :parachute :aoc/2024/21))
+
+(in-package :aoc/2024/21/tests)
+
+(define-test suite-2024-21
+                                        ;:parent suite-2024
+             )
+
+(define-test test-foo
+             :parent suite-2024-21
+             ) 
+
+
+(define-test test-bar
+             :parent suite-2024-21
+             )
+
+
+
+(define-test+run test-part1
+                 :parent suite-2024-21
+                 (is equal nil (part1 sample-data)))
+
+(define-test+run test-part2
+                 :parent suite-2024-21
+                 (is equal nil (part2 sample-data)))