diff --git a/lib/advent_code2024.ex b/lib/advent_code2024.ex
index 50127dd..6c84a98 100644
--- a/lib/advent_code2024.ex
+++ b/lib/advent_code2024.ex
@@ -4,15 +4,22 @@ defmodule AdventCode2024 do
   """
 
   @doc """
-  Hello world.
+  Calculates the total distance between two lists of numbers.
+  Lists are first sorted, then paired up, and the absolute differences are summed.
 
   ## Examples
 
-      iex> AdventCode2024.hello()
-      :world
+      iex> AdventCode2024.calculate_total_distance([3, 4, 2, 1, 3, 3], [4, 3, 5, 3, 9, 3])
+      11
+      iex> AdventCode2024.calculate_total_distance([], [])
+      0
+      iex> AdventCode2024.calculate_total_distance([1], [3])
+      2
 
   """
-  def hello do
-    :world
+  def calculate_total_distance(left_list, right_list) do
+    Enum.zip(Enum.sort(left_list), Enum.sort(right_list))
+    |> Enum.map(fn {a, b} -> abs(a - b) end)
+    |> Enum.sum()
   end
 end