diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9675b10
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+
+/.stack-work
+/data
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..3df2efc
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Justin Le (c) 2017
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Justin Le nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..3a804a8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,6 @@
+Advent of Code 2017
+===================
+
+**Warning: Spoilers**
+
+
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
index 0000000..9a994af
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/aoc2017.cabal b/aoc2017.cabal
new file mode 100644
index 0000000..8b19410
--- /dev/null
+++ b/aoc2017.cabal
@@ -0,0 +1,50 @@
+name:                aoc2017
+version:             0.1.0.0
+synopsis:            Short description of your package
+homepage:            https://github.com/mstksg/aoc2017#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Justin Le
+maintainer:          justin@jle.im
+copyright:           (c) Justin Le 2016
+category:            Web
+build-type:          Simple
+extra-source-files:  README.md
+cabal-version:       >=1.10
+
+-- To avoid duplicated efforts in documentation and dealing with the
+-- complications of embedding Haddock markup inside cabal files, it is
+-- common to point users to the README.md file.
+description:         Please see the README on Github at <https://github.com/mstksg/aoc2017#readme>
+
+library
+  hs-source-dirs:      src
+  exposed-modules:     AOC2017
+                       AOC2017.Day01
+                       AOC2017.Types
+  build-depends:       base >= 4.7 && < 5
+  default-language:    Haskell2010
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N -Wall
+
+executable aoc2017
+  hs-source-dirs:      app
+  main-is:             Main.hs
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N -Wall
+  build-depends:       base
+                     , aoc2017
+                     , containers
+                     , filepath
+  default-language:    Haskell2010
+
+test-suite aoc2017-test
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      test
+  main-is:             Spec.hs
+  build-depends:       base
+                     , aoc2017
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
+  default-language:    Haskell2010
+
+source-repository head
+  type:     git
+  location: https://github.com/mstksg/aoc2017
diff --git a/app/Main.hs b/app/Main.hs
new file mode 100644
index 0000000..bccf930
--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,19 @@
+
+
+import           AOC2017
+import           System.Environment
+import           System.FilePath
+import           Text.Printf
+import           Text.Read
+import qualified Data.IntMap        as IM
+
+tests :: IM.IntMap Challenge
+tests = IM.fromList [(1, day01)]
+
+main :: IO ()
+main = do
+    a:_ <- getArgs
+    let Just d = readMaybe a
+        Just t = IM.lookup d tests
+    putStrLn . t =<< readFile ("data" </> printf "%02d" d <.> "txt")
+
diff --git a/src/AOC2017.hs b/src/AOC2017.hs
new file mode 100644
index 0000000..86e79ad
--- /dev/null
+++ b/src/AOC2017.hs
@@ -0,0 +1,8 @@
+
+module AOC2017 (
+    module A
+  ) where
+
+import AOC2017.Day01 as A
+import AOC2017.Types as A
+
diff --git a/src/AOC2017/Day01.hs b/src/AOC2017/Day01.hs
new file mode 100644
index 0000000..2dcbca6
--- /dev/null
+++ b/src/AOC2017/Day01.hs
@@ -0,0 +1,15 @@
+
+module AOC2017.Day01 (day01) where
+
+import           AOC2017.Types
+import           Data.Char
+
+matchings :: Eq a => [a] -> [a]
+matchings []     = []
+matchings (x:xs) = map fst . filter (uncurry (==)) $ zip (x:xs) (xs ++ [x])
+
+sumMatchings :: (Num a, Eq a) => [a] -> a
+sumMatchings = sum . matchings
+
+day01 :: Challenge
+day01 = show . sumMatchings . map digitToInt . filter isDigit
diff --git a/src/AOC2017/Types.hs b/src/AOC2017/Types.hs
new file mode 100644
index 0000000..7c8bd50
--- /dev/null
+++ b/src/AOC2017/Types.hs
@@ -0,0 +1,7 @@
+
+module AOC2017.Types (
+    Challenge
+  ) where
+
+type Challenge = String -> String
+
diff --git a/stack.yaml b/stack.yaml
new file mode 100644
index 0000000..9e311c2
--- /dev/null
+++ b/stack.yaml
@@ -0,0 +1,66 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+# resolver: ghcjs-0.1.0_ghc-7.10.2
+# resolver:
+#  name: custom-snapshot
+#  location: "./custom-snapshot.yaml"
+resolver: lts-9.14
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#   extra-dep: true
+#  subdirs:
+#  - auto-update
+#  - wai
+#
+# A package marked 'extra-dep: true' will only be built if demanded by a
+# non-dependency (i.e. a user package), and its test suites and benchmarks
+# will not be run. This is useful for tweaking upstream packages.
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# (e.g., acme-missiles-0.3)
+extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+flags: {}
+
+# Extra package databases containing global packages
+extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.5"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor
\ No newline at end of file
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
index 0000000..cd4753f
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "Test suite not yet implemented"