diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..c84e79c
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,77 @@
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Run ShellCheck
+        uses: ludeeus/action-shellcheck@2.0.0
+        env:
+          SHELLCHECK_OPTS: --severity style --enable all --exclude SC2312 --shell bash
+        with:
+          check_together: yes
+          scandir: "./scripts"
+
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 3
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Get JDK version
+        run: |
+          source scripts/get_java_version.sh
+          echo "JAVA_VERSION=${JAVA_VERSION}" >> "${GITHUB_ENV}"
+
+      - name: Set up JDK ${{ env.JAVA_VERSION }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ env.JAVA_VERSION }}
+          distribution: "temurin"
+      - uses: sbt/setup-sbt@v1
+
+      - name: Run tests
+        run: sbt test
+
+  lint:
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Get JDK version
+        run: |
+          source scripts/get_java_version.sh
+          echo "JAVA_VERSION=${JAVA_VERSION}" >> "${GITHUB_ENV}"
+
+      - name: Set up JDK ${{ env.JAVA_VERSION }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ env.JAVA_VERSION }}
+          distribution: "temurin"
+      - uses: sbt/setup-sbt@v1
+
+      - name: Check
+        run: sbt scalafmtSbtCheck scalafmtCheck Test/scalafmtCheck
+
+  build-dockerfile:
+    runs-on: ubuntu-latest
+    timeout-minutes: 3
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build Dockerfile
+        run: docker build --file "./Dockerfile" "."
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ded7441
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,40 @@
+output/*
+logs
+target
+/.idea
+/.idea_modules
+/.classpath
+/.project
+/.settings
+/RUNNING_PID
+
+bin/
+.eclipse
+/lib/
+/logs/
+/modules
+/project/target
+/target
+project/project/
+tmp/
+test-result
+server.pid
+*.eml
+/dist/
+.cache
+*.rdb
+.DS_Store
+.tag*
+app/services/redis/
+/logs/application.log
+.sqitch/sqitch.conf
+.sqitch/templates
+.pgpass*
+db/data
+.ecr_token
+.bsp
+*.bloop
+.metals
+.vscode
+metals.sbt
+*.log
diff --git a/.mergify.yml b/.mergify.yml
new file mode 100644
index 0000000..7ed7914
--- /dev/null
+++ b/.mergify.yml
@@ -0,0 +1,23 @@
+pull_request_rules:
+
+- name: Automatically approve bot PRs
+  conditions: &base_merge_conditions
+  - status-success=shellcheck
+  - status-success=test
+  - status-success=lint
+  - status-success=build-dockerfile
+  - or:
+    - author=horothesun-scala-steward[bot]
+    - author=horothesun-renovate[bot]
+  actions:
+    review:
+      type: APPROVE
+
+- name: Automatically merge bot PRs
+  conditions:
+  - and: *base_merge_conditions
+  - and:
+    - "#approved-reviews-by>=1"
+  actions:
+    merge:
+      method: squash
diff --git a/.scala-steward.conf b/.scala-steward.conf
new file mode 100644
index 0000000..4400ac4
--- /dev/null
+++ b/.scala-steward.conf
@@ -0,0 +1 @@
+reviewers = [ "horothesun" ]
diff --git a/.scalafmt.conf b/.scalafmt.conf
new file mode 100644
index 0000000..d1ec73a
--- /dev/null
+++ b/.scalafmt.conf
@@ -0,0 +1,17 @@
+version = 3.8.3
+runner.dialect = scala3
+align.preset = some
+align.arrowEnumeratorGenerator = true
+align.openParenCallSite = true
+danglingParentheses.preset = true
+includeCurlyBraceInSelectChains = false
+maxColumn = 120
+newlines.penalizeSingleSelectMultiArgList = false
+optIn.breakChainOnFirstMethodDot = true
+optIn.configStyleArguments = true
+project.git = true
+rewrite.rules = [ Imports, RedundantBraces, RedundantParens, PreferCurlyFors ]
+rewrite.imports.sort = scalastyle
+rewrite.imports.groups = [ [".*"] ]
+runner.optimizer.forceConfigStyleOnOffset = 80
+style = IntelliJ # for pretty alignment
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..ef9b7c9
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,6 @@
+# The only purpose of this file is to get Renovate updates on the Temurin JDK version.
+# The CI uses the following JAVA_VERSION value to configure its JDK setup (through `scripts/get_java_version.sh`).
+
+ARG JAVA_VERSION=21
+
+FROM eclipse-temurin:${JAVA_VERSION}
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..11e636e
--- /dev/null
+++ b/README.md
@@ -0,0 +1,18 @@
+# Advent of Code 2024
+
+[![CI](https://github.com/horothesun/advent-of-code-2024/actions/workflows/ci.yml/badge.svg)](https://github.com/horothesun/advent-of-code-2024/actions/workflows/ci.yml)
+[![Renovate enabled](https://img.shields.io/badge/renovate-enabled-brightgreen.svg?style=flat-square)](https://renovatebot.com)
+[![Mergify enabled](https://img.shields.io/badge/Mergify-enabled-success.svg?style=flat-square&logo=data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAYAAABzenr0AAAAAXNSR0IArs4c6QAAAAlwSFlzAAALEwAACxMBAJqcGAAABCRpVFh0WE1MOmNvbS5hZG9iZS54bXAAAAAAADx4OnhtcG1ldGEgeG1sbnM6eD0iYWRvYmU6bnM6bWV0YS8iIHg6eG1wdGs9IlhNUCBDb3JlIDUuNC4wIj4KICAgPHJkZjpSREYgeG1sbnM6cmRmPSJodHRwOi8vd3d3LnczLm9yZy8xOTk5LzAyLzIyLXJkZi1zeW50YXgtbnMjIj4KICAgICAgPHJkZjpEZXNjcmlwdGlvbiByZGY6YWJvdXQ9IiIKICAgICAgICAgICAgeG1sbnM6dGlmZj0iaHR0cDovL25zLmFkb2JlLmNvbS90aWZmLzEuMC8iCiAgICAgICAgICAgIHhtbG5zOmV4aWY9Imh0dHA6Ly9ucy5hZG9iZS5jb20vZXhpZi8xLjAvIgogICAgICAgICAgICB4bWxuczpkYz0iaHR0cDovL3B1cmwub3JnL2RjL2VsZW1lbnRzLzEuMS8iCiAgICAgICAgICAgIHhtbG5zOnhtcD0iaHR0cDovL25zLmFkb2JlLmNvbS94YXAvMS4wLyI+CiAgICAgICAgIDx0aWZmOlJlc29sdXRpb25Vbml0PjI8L3RpZmY6UmVzb2x1dGlvblVuaXQ+CiAgICAgICAgIDx0aWZmOkNvbXByZXNzaW9uPjA8L3RpZmY6Q29tcHJlc3Npb24+CiAgICAgICAgIDx0aWZmOlhSZXNvbHV0aW9uPjcyPC90aWZmOlhSZXNvbHV0aW9uPgogICAgICAgICA8dGlmZjpPcmllbnRhdGlvbj4xPC90aWZmOk9yaWVudGF0aW9uPgogICAgICAgICA8dGlmZjpZUmVzb2x1dGlvbj43MjwvdGlmZjpZUmVzb2x1dGlvbj4KICAgICAgICAgPGV4aWY6UGl4ZWxYRGltZW5zaW9uPjMyPC9leGlmOlBpeGVsWERpbWVuc2lvbj4KICAgICAgICAgPGV4aWY6Q29sb3JTcGFjZT4xPC9leGlmOkNvbG9yU3BhY2U+CiAgICAgICAgIDxleGlmOlBpeGVsWURpbWVuc2lvbj4zMjwvZXhpZjpQaXhlbFlEaW1lbnNpb24+CiAgICAgICAgIDxkYzpzdWJqZWN0PgogICAgICAgICAgICA8cmRmOkJhZy8+CiAgICAgICAgIDwvZGM6c3ViamVjdD4KICAgICAgICAgPHhtcDpNb2RpZnlEYXRlPjIwMTktMDUtMjRUMTg6MDU6MjQ8L3htcDpNb2RpZnlEYXRlPgogICAgICAgICA8eG1wOkNyZWF0b3JUb29sPlBpeGVsbWF0b3IgMy44LjM8L3htcDpDcmVhdG9yVG9vbD4KICAgICAgPC9yZGY6RGVzY3JpcHRpb24+CiAgIDwvcmRmOlJERj4KPC94OnhtcG1ldGE+CpNRBfcAAAXOSURBVFgJxVddbFRFFD4z9+5PS3+E2pTyU6CitfxoUCSiDyRoVEjUh4bKkxbwzcSo8S8oMYRoYnw0PviAFDQRIZgYE4PRkGhihIJgkLZUKlQEC9SltNt0u3v//L5p73bb3aWURDnZuzN35pzznXPmzJm5SqZBi79JVNhDyaXK0itUIC2ByAMUVyJHAyWtgeefcMvK27vXVw3eqFrITk2NBy48qJQ8FwTB4xIEi3QkLoHn4HGNsLJsUVZEfGcE1qhzSqlvg0B2dzbNOzyV9usasGxvT6MXsd8BU5OKxOzAzQDUg074XpAUDLFE2VEJnLQLrgOW424/tXFhZ0F2DBY1oPHAX1uU0u8rO1LlZ+AZXJoWIWQ6iki5TiII/Dc6m+bvLCRf0IC79/e8q+3YVrg75nEh0RsbY0QQFvHd9HunNyx8a7JUngEGPFqyFSGcvteTtYfviAaWUPxMKs+ICQYs+aJns0RjO5lg0w55CFaspRFIVMmkt3Q8s/CTkC1rQMO+sw2WFflZlJ4ZZnfIxJYZkGXOnZhGn7tFAr/f85zVXc31XRTVobxW1g6EKQ/cA7LjB4YxjRd0xcUfx8K8zB0jfzGiY8QgVshjnFq67+yqwIr+hGy1s1rBQWW1pZa8ds9MmV1iyZG+EWn9PSk16Ee0knNJR65lfJkV0zKn1Ja4peTSsCe9KdfMF4wYl0JpV3mZh9ub69sQE0RFWZvNPk8Ph4Zl220rZknXtYx82H7NGPL1Y7XGADKc6s9IB56HauIydwaKEcYSaU92w8iPTw8K7MknhE1FUVN8bzMm23TDV33lcPQJFplcYngrIlrmwrM9Z5JyrC8tX54bkuq4JZ0waACeL5sZleb6MjPWPeDI+SFXqmKWvLL8NlkzOy5cskJkChowia21O7RUtK4brXDj7IgUQDzpGsjIi8sq5dG5pdJyV7lsP3FV1h3slTePJkxiplDvWn68Ik9912ueI1dQtECPgN8fVzehZ7CASWyN+N+vIzHA5VurYcUOAN5XFZO9a2skMeLLZ4gGAiM9Sdcko41+P8LOxOzH/K8J1A8QI1VwCcwskpqYxJZAt0wOv+HBH/LMgJ4FGOnvYdckJpeWcyFZTKyxsdANzuewhKzZ1mACW4Nr5eTwZ7nGlIaeTKU0V26qvsEEdrYOTCXwX81jCYJj5sAogsAiEyYz+2GIwzGK8dwlsQnHycunGBnMQI4hAmoXz+9CRAVVcS315aZcmGJjY2EJUod9z2LEZzHmaQTn6spGedmyQBUzwmAqv1WL9o77Thri+SnjoxiwEB1HZm88dBnGWNKEfX872peXV8rrbQl56fA/ZpuyEjYtKkPFtA0vt+PbkKWOfFK4PQFTBb/Yvl3WrjPD53FQLMg9hChXGbWkoTIqLT9clu5BBxGwZE1tifSlPPPsOTNoKve6eaVy76yorEZF/PyPpHx/cRjb1JHWNTVGx5Djo/yOm8HwA+u8HwV219PVScwdnLwMFBiE4EVsvWfvLJeV1THj4cmrGTmDqlcLj5+smyHr58+QOyoichoF67eracNDXspQljpywWkGsYg5hi1yo4dRGw6jjzoGZAQLvnZOiWxqqDCn5KfdSTl4YdgcRi8sqZRV1XG5hCh9cLJfenE4hdvYxIA1I+cwygamcf+f+3SsZIOfTo3HCj0mHNcximQbwUsU2iiUQXbZVIa+MzbP1c6Ah6ci51lJJ4BjHhgCjP2dGxY049U4wBYg3jZcw/rNpcGMjP5RATOddT02Bs4ZGoSfCS/7JP6Th7yUmQxO3cQgFvlJ2UJkbiiu9ypuRKNaR+ez/6MQ2dfrdgryMhGoGxjhbYhKsgbwhXc13l55gczLHDLcLHGpeCmF7tz7INUVNPb/vJZPiEDoIO/vWKvnYV+CSXNT0YDXRhY6qKvQN0HRCISG3NJPs9AItrfs4zTXCPb5eR5JpZbg2FuBzbYJ+37881z0LmTUCaekpGM6n+f/AiQDwkIqcbgQAAAAAElFTkSuQmCC)](https://mergify.com)
+[![Scala](https://img.shields.io/badge/Scala-3-%23DC322F?style=flat&labelColor=%23383838&logo=Scala&logoColor=%23DC322F&logoWidth=12&cacheSeconds=3600)](https://www.scala-lang.org/)
+
+Initialise a new day by running
+
+```bash
+scripts/init_day.sh <DAY-NUMBER>
+```
+
+Test specific day with
+
+```bash
+sbt "~testOnly *DayXSuite*"
+```
diff --git a/build.sbt b/build.sbt
new file mode 100644
index 0000000..5faf20d
--- /dev/null
+++ b/build.sbt
@@ -0,0 +1,59 @@
+val catsVersion = "2.12.0"
+
+val kittensVersion = "3.4.0"
+
+val catsParseVersion = "1.0.0"
+
+val catsEffectVersion = "3.5.7"
+
+val fs2Version = "3.11.0"
+
+val drosteVersion = "0.9.0"
+
+val munitVersion = "1.0.2"
+
+val munitScalacheckVersion = "1.0.0"
+
+val munitCatsEffectVersion = "2.0.0"
+
+val scalacheckVersion = "1.18.1"
+
+val scalacheckEffectMunitVersion = "1.0.4"
+
+val disciplineMunitVersion = "2.0.0"
+
+lazy val root = project
+  .in(file("."))
+  .settings(
+    organization := "com.horothesun",
+    name := "advent-of-code-2023",
+    scalaVersion := "3.5.2",
+    libraryDependencies ++= Seq(
+      "org.typelevel" %% "cats-core" % catsVersion,
+      "org.typelevel" %% "kittens" % kittensVersion,
+      "org.typelevel" %% "cats-parse" % catsParseVersion,
+      "org.typelevel" %% "cats-effect" % catsEffectVersion,
+      "co.fs2" %% "fs2-core" % fs2Version,
+      "io.higherkindness" %% "droste-core" % drosteVersion,
+      "org.scalameta" %% "munit" % munitVersion % Test,
+      "org.typelevel" %% "munit-cats-effect" % munitCatsEffectVersion % Test,
+      "org.scalameta" %% "munit-scalacheck" % munitScalacheckVersion % Test,
+      "org.scalacheck" %% "scalacheck" % scalacheckVersion % Test,
+      "org.typelevel" %% "scalacheck-effect-munit" % scalacheckEffectMunitVersion % Test,
+      "org.typelevel" %% "cats-effect-testkit" % catsEffectVersion % Test,
+      "org.typelevel" %% "cats-laws" % catsVersion % Test,
+      "org.typelevel" %% "discipline-munit" % disciplineMunitVersion % Test
+    ),
+    scalacOptions ++= Seq(
+      "-deprecation",
+      "-encoding",
+      "UTF-8",
+      "-feature",
+      "-unchecked",
+      "-language:postfixOps",
+      "-source:future",
+      "-explain",
+      "-Wvalue-discard",
+      "-Wunused:all"
+    )
+  )
diff --git a/project/build.properties b/project/build.properties
new file mode 100644
index 0000000..e88a0d8
--- /dev/null
+++ b/project/build.properties
@@ -0,0 +1 @@
+sbt.version=1.10.6
diff --git a/project/plugins.sbt b/project/plugins.sbt
new file mode 100644
index 0000000..7d517ef
--- /dev/null
+++ b/project/plugins.sbt
@@ -0,0 +1 @@
+addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")
diff --git a/scripts/get_java_version.sh b/scripts/get_java_version.sh
new file mode 100755
index 0000000..ef5aea0
--- /dev/null
+++ b/scripts/get_java_version.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+JAVA_VERSION=$(grep "ARG JAVA_VERSION=" "Dockerfile" | grep -o "[^=]*$")
+
+[[ -z "${JAVA_VERSION}" ]] && echo "Error: JAVA_VERSION not found in Dockerfile" && exit 123
+
+export JAVA_VERSION
diff --git a/scripts/init_day.sh b/scripts/init_day.sh
new file mode 100755
index 0000000..2e347b7
--- /dev/null
+++ b/scripts/init_day.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+AOC_DAY="$1"
+
+[[ -z "${AOC_DAY}" ]] && echo "Error: AoC day must be passed as first argument" && exit 10
+
+cat <<EOT >> "src/main/scala/Day${AOC_DAY}.scala"
+import cats.derived.*
+import cats.syntax.all.*
+
+object Day${AOC_DAY}:
+
+  def day${AOC_DAY}: Int = 42
+EOT
+
+touch "src/test/scala/day${AOC_DAY}_input.txt"
+
+cat <<EOT >> "src/test/scala/Day${AOC_DAY}Suite.scala"
+import Day${AOC_DAY}.*
+import Day${AOC_DAY}Suite.*
+import munit.ScalaCheckSuite
+import org.scalacheck.Gen
+import org.scalacheck.Prop.*
+
+class Day${AOC_DAY}Suite extends ScalaCheckSuite:
+
+  test("day${AOC_DAY} == 42"):
+    assertEquals(day${AOC_DAY}, 42)
+
+object Day${AOC_DAY}Suite:
+
+  val bigInput: List[String] = getLinesFromFile("src/test/scala/day${AOC_DAY}_input.txt")
+EOT
diff --git a/src/main/scala/Day01.scala b/src/main/scala/Day01.scala
new file mode 100644
index 0000000..7189d38
--- /dev/null
+++ b/src/main/scala/Day01.scala
@@ -0,0 +1,6 @@
+import cats.derived.*
+import cats.syntax.all.*
+
+object Day01:
+
+  def day01: Int = 42
diff --git a/src/test/scala/Day01Suite.scala b/src/test/scala/Day01Suite.scala
new file mode 100644
index 0000000..26bdca0
--- /dev/null
+++ b/src/test/scala/Day01Suite.scala
@@ -0,0 +1,14 @@
+import munit.ScalaCheckSuite
+import org.scalacheck.Gen
+import org.scalacheck.Prop.*
+import Day01.*
+import Day01Suite.*
+
+class Day01Suite extends ScalaCheckSuite:
+
+  test("day01 == 42"):
+    assertEquals(day01, 42)
+
+object Day01Suite:
+
+  val bigInput: List[String] = getLinesFromFile("src/test/scala/day01_input.txt")
diff --git a/src/test/scala/FileLoader.scala b/src/test/scala/FileLoader.scala
new file mode 100644
index 0000000..e95cc5b
--- /dev/null
+++ b/src/test/scala/FileLoader.scala
@@ -0,0 +1,7 @@
+import scala.io.Source
+
+def getLinesFromFile(filename: String): List[String] =
+  val source = Source.fromFile(filename)
+  val result = source.getLines().toList
+  source.close
+  result
diff --git a/src/test/scala/day01_input.txt b/src/test/scala/day01_input.txt
new file mode 100644
index 0000000..e69de29