diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..fdddb29
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <https://unlicense.org>
diff --git a/README.md b/README.md
index e8915a9..8843a25 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
-This is a collection of solutions to common interview problems, written in
-Python and Haskell. These are just ones that I've come across or that I've seen
-as popular questions. Pull requests are much appreciated!
+This is a collection of solutions to common algorithms, written in
+various programming languages.
+
+All code is written completely by me, and is placed in the public domain.
diff --git a/sorted_digits.hs b/sorted_digits.hs
new file mode 100644
index 0000000..456ad52
--- /dev/null
+++ b/sorted_digits.hs
@@ -0,0 +1,18 @@
+import Data.List
+
+digits :: Int -> [Int]
+digits n = unfoldr nextDigit n where
+  nextDigit 0 = Nothing
+  nextDigit c = Just (c `mod` 10, c `div` 10)
+
+isSorted :: Int -> Bool
+isSorted n = all (uncurry (<=)) ds' || all (uncurry (>=)) ds''
+  where ds = digits n
+        ds' = zip ds (maxBound : ds)
+        ds'' = zip ds (minBound : ds)
+
+main = do
+  print $ isSorted 123456
+  print $ isSorted 1234561
+  print $ isSorted 97541
+  print $ isSorted 99431