diff --git a/src/gloat.gleam b/src/gloat.gleam
index 16f1ce1..0f7fd78 100644
--- a/src/gloat.gleam
+++ b/src/gloat.gleam
@@ -13,6 +13,7 @@ import solve_2025_05
 import solve_2025_06
 import solve_2025_07
 import solve_2025_08
+import solve_2025_09
 
 pub fn main() -> Nil {
   case argv.load().arguments {
@@ -37,6 +38,8 @@ pub fn main() -> Nil {
       display(#(2025, 7), solve_2025_07.part_one, solve_2025_07.part_two)
     ["2025", "8"] ->
       display(#(2025, 8), solve_2025_08.part_one, solve_2025_08.part_two)
+    ["2025", "9"] ->
+      display(#(2025, 9), solve_2025_09.part_one, solve_2025_09.part_two)
     ["2025", _] -> io.print("No solutions for 2025")
     _ -> io.print("Please provide the following arguments: <year> <day>")
   }
diff --git a/src/solve_2025_09.gleam b/src/solve_2025_09.gleam
new file mode 100644
index 0000000..077faa7
--- /dev/null
+++ b/src/solve_2025_09.gleam
@@ -0,0 +1,54 @@
+import gleam/int
+import gleam/list
+import gleam/result
+import gleam/string
+
+type Tile {
+  Tile(x: Int, y: Int)
+}
+
+type Rectangle {
+  Rectangle(south_west: Tile, north_east: Tile, area: Int)
+}
+
+fn area(south_west: Tile, north_east: Tile) {
+  let dx = north_east.x - south_west.x |> int.absolute_value |> int.add(1)
+  let dy = north_east.y - south_west.y |> int.absolute_value |> int.add(1)
+  dx * dy
+}
+
+fn compare(left: Rectangle, right: Rectangle) {
+  int.compare(left.area, right.area)
+}
+
+pub fn part_one(input: String) -> Int {
+  input
+  |> parse
+  |> list.combination_pairs
+  |> list.map(fn(pair) {
+    let #(south_west, north_east) = pair
+    let area = area(south_west, north_east)
+    Rectangle(south_west:, north_east:, area:)
+  })
+  |> list.sort(compare)
+  // |> echo
+  |> list.reverse
+  |> list.map(fn(rectangle) { rectangle.area })
+  |> list.first
+  |> result.unwrap(-1)
+}
+
+pub fn part_two(input: String) -> Int {
+  // echo parse(input)
+  -1
+}
+
+fn parse(input: String) -> List(Tile) {
+  use line <- list.flat_map(input |> string.trim |> string.split("\n"))
+  case
+    line |> string.split(",") |> list.map(string.trim) |> list.map(int.parse)
+  {
+    [Ok(x), Ok(y)] -> [Tile(x:, y:)]
+    _ -> [] |> echo |> list.take(0)
+  }
+}
diff --git a/test/test_2025_09.gleam b/test/test_2025_09.gleam
new file mode 100644
index 0000000..29ac6aa
--- /dev/null
+++ b/test/test_2025_09.gleam
@@ -0,0 +1,29 @@
+import gleam/string
+import solve_2025_09
+
+const input = "
+7,1
+11,1
+11,7
+9,7
+9,5
+2,5
+2,3
+7,3
+"
+
+pub fn part_one_test() {
+  let result =
+    input
+    |> string.trim
+    |> solve_2025_09.part_one
+  assert result == 50
+}
+
+pub fn part_two_test() {
+  let result =
+    input
+    |> string.trim
+    |> solve_2025_09.part_two
+  assert result == -1
+}