diff --git a/2015/README.md b/2015/README.md
index d1e2675..32fbaa1 100644
--- a/2015/README.md
+++ b/2015/README.md
@@ -12,12 +12,12 @@
   ```
 </details>
 
-|  S  |  M  |  T  |  W  |  T   |  F   |  S  |
-| :-: | :-: | :-: | :-: | :-:  | :-:  | :-: |
-|     |     | [1] | [2] | [3]  | [4]  | [5] |
-| [6] | [7] | [8] | [9] | [10] | [11] | 12  |
-| 13  | 14  | 15  | 16  | 17   | 18   | 19  |
-| 20  | 21  | 22  | 23  | 24   | 25   |     |
+|  S  |  M  |  T  |  W  |  T   |  F   |  S   |
+| :-: | :-: | :-: | :-: | :-:  | :-:  | :-:  |
+|     |     | [1] | [2] | [3]  | [4]  | [5]  |
+| [6] | [7] | [8] | [9] | [10] | [11] | [12] |
+| 13  | 14  | 15  | 16  | 17   | 18   | 19   |
+| 20  | 21  | 22  | 23  | 24   | 25   |      |
 
 [1]: ./lib/2015/1.ex
 [2]: ./lib/2015/2.ex
@@ -30,3 +30,4 @@
 [9]: ./lib/2015/9.ex
 [10]: ./lib/2015/10.ex
 [11]: ./lib/2015/11.ex
+[12]: ./lib/2015/12.ex
diff --git a/2015/lib/2015/12.ex b/2015/lib/2015/12.ex
new file mode 100644
index 0000000..4f89431
--- /dev/null
+++ b/2015/lib/2015/12.ex
@@ -0,0 +1,42 @@
+import AOC
+
+aoc 2015, 12 do
+  def p1 do
+    input_stream()
+    |> Stream.flat_map(fn l ->
+      Regex.scan(~r/-?\d+/, l)
+      |> List.flatten()
+    end)
+    |> Stream.map(&String.to_integer/1)
+    |> Enum.sum()
+  end
+
+  def p2 do
+    input_string()
+    |> String.trim()
+    |> Jason.decode!()
+    |> count_document()
+  end
+
+  def count_document(document) when is_map(document) do
+    values = Map.values(document)
+
+    if Enum.member?(values, "red") do
+      0
+    else
+      document
+      |> Map.values()
+      |> Enum.map(&count_document/1)
+      |> Enum.sum()
+    end
+  end
+
+  def count_document(document) when is_list(document) do
+    document
+    |> Enum.map(&count_document/1)
+    |> Enum.sum()
+  end
+
+  def count_document(document) when is_number(document), do: document
+  def count_document(_), do: 0
+end
diff --git a/2015/mix.exs b/2015/mix.exs
index 853ea3f..070dc2d 100644
--- a/2015/mix.exs
+++ b/2015/mix.exs
@@ -23,6 +23,7 @@ defmodule AdventOfCode2015.MixProject do
     [
       {:advent_of_code_utils, "~> 1.0"},
       {:exla, "~> 0.1.0-dev", github: "elixir-nx/nx", sparse: "exla"},
+      {:jason, "~> 1.2"},
       {:libgraph, "~> 0.13.3"},
       {:nimble_parsec, "~> 1.0"},
       {:nx, "~> 0.1.0-dev", github: "elixir-nx/nx", sparse: "nx", override: true}
diff --git a/2015/mix.lock b/2015/mix.lock
index 236fcce..84c18b9 100644
--- a/2015/mix.lock
+++ b/2015/mix.lock
@@ -2,6 +2,7 @@
   "advent_of_code_utils": {:hex, :advent_of_code_utils, "1.0.0", "e9ce8be22988e095991168e9d2dde802afc213aaae64491e9fde84dd877db41c", [:mix], [], "hexpm", "1fa5217ccb95a38ce2312dd7ea6057b0d0002a3eba7490feab704df4b8a94038"},
   "elixir_make": {:hex, :elixir_make, "0.6.3", "bc07d53221216838d79e03a8019d0839786703129599e9619f4ab74c8c096eac", [:mix], [], "hexpm", "f5cbd651c5678bcaabdbb7857658ee106b12509cd976c2c2fca99688e1daf716"},
   "exla": {:git, "https://github.com/elixir-nx/nx.git", "e23a678bf0ebcbbafe03f1b5ed78623f052ad486", [sparse: "exla"]},
+  "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
   "libgraph": {:hex, :libgraph, "0.13.3", "20732b7bafb933dcf7351c479e03076ebd14a85fd3202c67a1c197f4f7c2466b", [:mix], [], "hexpm", "78f2576eef615440b46f10060b1de1c86640441422832052686df53dc3c148c6"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.2.0", "b44d75e2a6542dcb6acf5d71c32c74ca88960421b6874777f79153bbbbd7dccc", [:mix], [], "hexpm", "52b2871a7515a5ac49b00f214e4165a40724cf99798d8e4a65e4fd64ebd002c1"},
   "nx": {:git, "https://github.com/elixir-nx/nx.git", "e23a678bf0ebcbbafe03f1b5ed78623f052ad486", [sparse: "nx"]},