diff --git a/puzzles/day05.py b/puzzles/day05.py
index cf883a8..c491242 100644
--- a/puzzles/day05.py
+++ b/puzzles/day05.py
@@ -42,7 +42,6 @@ class Chart:
     vents: List = None
 
     def __init__(self, vents: List[VolcanicVent], diagnals: bool = True) -> None:
-        self.chart = defaultdict(int)
         self.vents = vents
         self._generate_chart(diagnals=diagnals)
 
@@ -59,22 +58,22 @@ class Chart:
         ..........
         222111....      0,9 -> 5,9      0,9 -> 2,9
         """
-        vents = self.vents.copy()
-        for vent in vents:
+        self.chart = defaultdict(int)
+        for vent in self.vents:
             if vent.direction != "diagnal":
                 self._chart_line_horiz_vert(vent.start, vent.end)
             elif diagnals:
                 self._chart_line_diagnal(vent.start, vent.end)
 
     def _chart_line_diagnal(self, start: Location, end: Location) -> None:
-        if end.x > start.x: # direction: left
+        if end.x > start.x:  # direction: left
             x_range = range(start.x, end.x + 1)
-        else:   # direction: right
-            x_range = range(start.x, end.x - 1, -1) # reverse range
-        if end.y > start.y: # direction: down
+        else:  # direction: right
+            x_range = range(start.x, end.x - 1, -1)  # reverse range
+        if end.y > start.y:  # direction: down
             y_range = range(start.y, end.y + 1)
-        else:   # direction: up
-            y_range = range(start.y, end.y - 1, -1) # reverse range
+        else:  # direction: up
+            y_range = range(start.y, end.y - 1, -1)  # reverse range
 
         for x, y in zip(x_range, y_range):
             self.chart[x, y] += 1