diff --git a/tools/aoc.py b/tools/aoc.py
index 2dca347..d8d3ced 100644
--- a/tools/aoc.py
+++ b/tools/aoc.py
@@ -1,5 +1,7 @@
 import os
 import re
+import subprocess
+
 import requests
 import time
 import webbrowser
@@ -91,9 +93,11 @@ class AOCDay:
             f.write(response.content)
             f.flush()
 
+        if os.path.exists(".git"):
+            subprocess.call(["git", "add", filename])
+
     def _submit(self, part: int, answer: Any):
         answer_cache = JSONFile("answer_cache.json", create=True)
-        print(answer_cache)
         str_day = str(self.day)
         str_part = str(part)
         if str_day not in answer_cache:
diff --git a/tools/coordinate.py b/tools/coordinate.py
index 6057cec..17a457d 100644
--- a/tools/coordinate.py
+++ b/tools/coordinate.py
@@ -174,7 +174,7 @@ class Coordinate:
     @staticmethod
     def generate(from_x: int, to_x: int, from_y: int, to_y: int,
                  from_z: int = None, to_z: int = None) -> List[Coordinate]:
-        if from_z is None and to_z is None:
+        if from_z is None or to_z is None:
             return [Coordinate(x, y) for x in range(from_x, to_x + 1) for y in range(from_y, to_y + 1)]
         else:
             return [
@@ -183,3 +183,84 @@ class Coordinate:
                 for y in range(from_y, to_y + 1)
                 for z in range(from_z, to_z + 1)
             ]
+
+
+class Shape:
+    top_left: Coordinate
+    bottom_right: Coordinate
+    mode_3d: bool
+
+    def __init__(self, top_left: Coordinate, bottom_right: Coordinate):
+        """
+        in 2D mode: top_left is the upper left corner and bottom_right the lower right
+                    (top_left.x <= bottom_right.x and top_left.y <= bottom_right.y)
+        in 3D mode: same logic applied, just for 3D Coordinates
+                    top_left is the upper left rear corner and bottom_right the lower right front
+                    (top_left.x <= bottom_right.x and top_left.y <= bottom_right.y and top_left.z <= bottom_right.z)
+        """
+        self.top_left = top_left
+        self.bottom_right = bottom_right
+        self.mode_3d = top_left.z is not None and bottom_right.z is not None
+
+    def size(self):
+        if not self.mode_3d:
+            return (self.bottom_right.x - self.top_left.x + 1) * (self.bottom_right.y - self.top_left.y + 1)
+        else:
+            return (
+                (self.bottom_right.x - self.top_left.x + 1)
+                * (self.bottom_right.y - self.top_left.y + 1)
+                * (self.bottom_right.z - self.top_left.z + 1)
+            )
+
+    def intersection(self, other: Shape) -> Union[Shape, None]:
+        """
+        returns a Shape of the intersecting part, or None if the Shapes don't intersect
+        """
+        if self.mode_3d != other.mode_3d:
+            raise ValueError("Cannot calculate intersection between 2d and 3d shape")
+
+        if not self.mode_3d:
+            intersect_top_left = Coordinate(
+                self.top_left.x if self.top_left.x > other.top_left.x else other.top_left.x,
+                self.top_left.y if self.top_left.y > other.top_left.y else other.top_left.y,
+            )
+            intersect_bottom_right = Coordinate(
+                self.bottom_right.x if self.bottom_right.x < other.bottom_right.x else other.bottom_right.x,
+                self.bottom_right.y if self.bottom_right.y < other.bottom_right.y else other.bottom_right.y,
+            )
+        else:
+            intersect_top_left = Coordinate(
+                self.top_left.x if self.top_left.x > other.top_left.x else other.top_left.x,
+                self.top_left.y if self.top_left.y > other.top_left.y else other.top_left.y,
+                self.top_left.z if self.top_left.z > other.top_left.z else other.top_left.z,
+            )
+            intersect_bottom_right = Coordinate(
+                self.bottom_right.x if self.bottom_right.x < other.bottom_right.x else other.bottom_right.x,
+                self.bottom_right.y if self.bottom_right.y < other.bottom_right.y else other.bottom_right.y,
+                self.bottom_right.z if self.bottom_right.z < other.bottom_right.z else other.bottom_right.z,
+            )
+
+        if intersect_top_left <= intersect_bottom_right:
+            return self.__class__(intersect_top_left, intersect_bottom_right)
+
+    def __and__(self, other):
+        return self.intersection(other)
+
+    def __rand__(self, other):
+        return self.intersection(other)
+
+    def __str__(self):
+        return "%s(%s, %s)" % (self.__class__.__name__, self.top_left, self.bottom_right)
+
+
+class Square(Shape):
+    def __init__(self, top_left, bottom_right):
+        super().__init__(top_left, bottom_right)
+        self.mode_3d = False
+
+
+class Cube(Shape):
+    def __init__(self, top_left, bottom_right):
+        if top_left.z is None or bottom_right.z is None:
+            raise ValueError("Both Coordinates need to be 3D")
+        super().__init__(top_left, bottom_right)