diff --git a/input/2023/day_11/input_test.txt b/input/2023/day_11/input_test.txt
new file mode 100644
index 0000000..a0bda53
--- /dev/null
+++ b/input/2023/day_11/input_test.txt
@@ -0,0 +1,10 @@
+...#......
+.......#..
+#.........
+..........
+......#...
+.#........
+.........#
+..........
+.......#..
+#...#.....
\ No newline at end of file
diff --git a/src/year_2023/day_11_cosmic_expantion/mod.rs b/src/year_2023/day_11_cosmic_expantion/mod.rs
new file mode 100644
index 0000000..744b964
--- /dev/null
+++ b/src/year_2023/day_11_cosmic_expantion/mod.rs
@@ -0,0 +1,25 @@
+pub mod part_one;
+//pub mod part_two;
+//pub mod common;
+
+use crate::utils::solution::Solution;
+use crate::utils::input_reader;
+
+pub struct DaySolution ;
+
+
+impl Solution for DaySolution {
+
+    fn input_path(&self) -> &'static str {
+        "input/2023/day_11/input_test.txt"
+    }
+
+    fn part_one(&self) -> String {
+        input_reader::read_input_file(self.input_path(), part_one::part_one)
+    }
+
+    fn part_two(&self) -> String {
+        //input_reader::read_input_file(self.input_path, part_two::part_two)
+        String::from("Not implemented")
+    }
+}
\ No newline at end of file
diff --git a/src/year_2023/day_11_cosmic_expantion/part_one.rs b/src/year_2023/day_11_cosmic_expantion/part_one.rs
new file mode 100644
index 0000000..4a535c7
--- /dev/null
+++ b/src/year_2023/day_11_cosmic_expantion/part_one.rs
@@ -0,0 +1,51 @@
+pub fn part_one(input_lines: Vec<String>) -> String {
+    let vert_dim = input_lines.len();
+    let horz_dim = input_lines[0].len();
+
+    let mut matrix = vec![vec![false; horz_dim]; vert_dim];
+
+    for (y, line) in input_lines.iter().enumerate() {
+        for (x, c) in line.chars().enumerate() {
+            matrix[x][y] = c == '#';
+        }
+    }
+
+    println!("Pre-expand dims: {:?}, {:?}", matrix.len(), matrix[0].len());
+
+    expand_rows(&mut matrix);
+    expand_cols(&mut matrix);
+
+    println!("Post-expand dims: {:?}, {:?}", matrix.len(), matrix[0].len());
+
+    String::from("Not implemented")
+}
+
+fn expand_rows(matrix: &mut Vec<Vec<bool>>) {
+    let mut i = 0;
+    while i < matrix.len() {
+        let row = matrix[i].clone();
+        if all_false(&row) {
+            matrix.insert(i, row.clone());
+            i += 1;
+        }
+        i += 1;
+    }
+}
+
+fn expand_cols(matrix: &mut Vec<Vec<bool>>) {
+    let mut i = 0;
+    while i < matrix[0].len() {
+        let col = matrix.iter().map(|row| row[i]).collect::<Vec<bool>>();
+        if all_false(&col) {
+            for row in matrix.iter_mut() {
+                row.insert(i, false);
+            }
+            i += 1;
+        }
+        i += 1;
+    }
+}
+
+fn all_false(vector: &Vec<bool>) -> bool {
+    vector.iter().all(|x| *x == false)
+}
\ No newline at end of file
diff --git a/src/year_2023/mod.rs b/src/year_2023/mod.rs
index 7cfc9b1..9a7cd43 100644
--- a/src/year_2023/mod.rs
+++ b/src/year_2023/mod.rs
@@ -8,6 +8,7 @@ pub mod day_06_wait_for_it;
 pub mod day_08_haunted_wasteland;
 pub mod day_09_mirage_maintenance;
 pub mod day_10_pipe_maze;
+pub mod day_11_cosmic_expantion;
 
 pub fn run(day: &str) {
     let solution: Box<dyn Solution> = match day {
@@ -19,6 +20,7 @@ pub fn run(day: &str) {
         "8" => Box::new(day_08_haunted_wasteland::DaySolution),
         "9" => Box::new(day_09_mirage_maintenance::DaySolution),
         "10" => Box::new(day_10_pipe_maze::DaySolution),
+        "11" => Box::new(day_11_cosmic_expantion::DaySolution),
         _ => panic!("Invalid day specified"),
     };