diff --git a/assets/day_12_garden_input b/assets/day_12_garden_input
new file mode 100644
index 0000000..85b768f
--- /dev/null
+++ b/assets/day_12_garden_input
@@ -0,0 +1,10 @@
+RRRRIICCFF
+RRRRIICCCF
+VVRRRCCFFF
+VVRCCCJFFF
+VVVVCJJCFE
+VVIVCCJJEE
+VVIIICJJEE
+MIIIIIJJEE
+MIIISIJEEE
+MMMISSJEEE
diff --git a/src/advent_of_code/mod.rs b/src/advent_of_code/mod.rs
index c1c4731..f1ab46a 100644
--- a/src/advent_of_code/mod.rs
+++ b/src/advent_of_code/mod.rs
@@ -98,4 +98,8 @@ pub fn historian_hysteria() {
     //     "The total of stones after {} is {}",
     //     blink_count, stone_count
     // );
+
+    // Thursday 12
+    let fence_cost = thu_12::garden_groups("./assets/day_12_garden_input");
+    println!("The garden fence total cost is {}", fence_cost);
 }
diff --git a/src/advent_of_code/thu_12.rs b/src/advent_of_code/thu_12.rs
index b7b1be3..139e733 100644
--- a/src/advent_of_code/thu_12.rs
+++ b/src/advent_of_code/thu_12.rs
@@ -1,16 +1,114 @@
 use super::*;
 
-pub fn garden_groups(input: &str) {
+pub fn garden_groups(input: &str) -> usize {
     let garden = utils::read_garden_arrangement_input(input);
+
+    let plot_list = get_plot_list(&garden);
+
+    let mut total_cost: usize = 0;
+
+    for plot in plot_list {
+        println!("Plot: {:?}", plot);
+        total_cost += plot.side_count * plot.plant_list.len();
+    }
+
+    total_cost
 }
 
-pub fn get_plot_list(map: &Garden) -> Plot {
-    let plot = Plot{}
+pub fn get_plot_list(map: &Garden) -> PlotList {
+    let mut plot_list: PlotList = vec![];
+
+    for (row_index, row) in map.iter().enumerate() {
+        for (plant_index, plant) in row.iter().enumerate() {
+            let new_coord = Coordinate {
+                x: plant_index,
+                y: row_index,
+            };
+            // FIXME: this does not cover all the cases! Any linear plot wont be covered
+            if row_index > 0 {
+                if let Some(plot_index) = which_plot_contains_coords(
+                    &plot_list,
+                    Coordinate {
+                        x: plant_index,
+                        y: row_index - 1,
+                    },
+                ) {
+                    if plot_list[plot_index].plant == *plant {
+                        plot_list[plot_index].plant_list.push(new_coord);
+                        plot_list[plot_index].side_count += calc_sides_of_plant(
+                            map,
+                            &Coordinate {
+                                x: plant_index,
+                                y: row_index,
+                            },
+                            plant,
+                        );
+                        continue;
+                    }
+                }
+            }
+            if plant_index > 0 {
+                if let Some(plot_index) = which_plot_contains_coords(
+                    &plot_list,
+                    Coordinate {
+                        x: plant_index - 1,
+                        y: row_index,
+                    },
+                ) {
+                    if plot_list[plot_index].plant == *plant {
+                        plot_list[plot_index].plant_list.push(new_coord);
+                        plot_list[plot_index].side_count += calc_sides_of_plant(
+                            map,
+                            &Coordinate {
+                                x: plant_index,
+                                y: row_index,
+                            },
+                            plant,
+                        );
+
+                        continue;
+                    }
+                }
+            }
+
+            plot_list.push(Plot {
+                plant: *plant,
+                side_count: calc_sides_of_plant(map, &new_coord, plant),
+                plant_list: vec![new_coord],
+            });
+        }
+    }
+
+    plot_list
 }
 
-pub fn which_plot_contains_coords(list: &PlotList, coord: Coorinate) -> Option<usize> {
+pub fn calc_sides_of_plant(map: &Garden, coord: &Coordinate, plant: &Plant) -> usize {
+    let mut sum: usize = 0;
+
+    if coord.x == 0 || map[coord.y][coord.x - 1] != *plant {
+        sum += 1;
+    }
+
+    if coord.y == 0 || map[coord.y - 1][coord.x] != *plant {
+        sum += 1;
+    }
+
+    if coord.x < map[0].len() - 2 && map[coord.y][coord.x + 1] != *plant
+        || coord.x == map[0].len() - 1
+    {
+        sum += 1;
+    }
+
+    if coord.y < map.len() - 2 && map[coord.y + 1][coord.x] != *plant || coord.y == map.len() - 1 {
+        sum += 1;
+    }
+
+    sum
+}
+
+pub fn which_plot_contains_coords(list: &PlotList, coord: Coordinate) -> Option<usize> {
     for (plot_index, plot) in list.iter().enumerate() {
-        if plot.plant_list.contains(coord) {
+        if plot.plant_list.contains(&coord) {
             return Some(plot_index);
         }
     }
diff --git a/src/advent_of_code/types.rs b/src/advent_of_code/types.rs
index 86f1a04..090bdd3 100644
--- a/src/advent_of_code/types.rs
+++ b/src/advent_of_code/types.rs
@@ -91,11 +91,13 @@ pub type StoneList = Vec<Stone>;
 pub type Plant = char;
 pub type Garden = Vec<Vec<char>>;
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Debug)]
 pub struct Coordinate {
     pub x: usize,
     pub y: usize,
 }
+
+#[derive(Debug)]
 pub struct Plot {
     pub plant: Plant,
     pub side_count: usize,
diff --git a/src/advent_of_code/utils.rs b/src/advent_of_code/utils.rs
index ab51c59..39bc792 100644
--- a/src/advent_of_code/utils.rs
+++ b/src/advent_of_code/utils.rs
@@ -1,5 +1,4 @@
 use std::fs::read_to_string;
-use std::io::read_to_string;
 use std::ops::Sub;
 
 use super::*;