diff --git a/aoc.py b/aoc.py
index 4f90fc9..20738e8 100644
--- a/aoc.py
+++ b/aoc.py
@@ -125,7 +125,7 @@ class Aoc(Generic[T1], Aoc2[T1, T1]):
         return self.part1(inpt)
 
 
-def main():
+def main() -> None:
     days = [
         import_module(file.stem)
         for file in Path(".").iterdir()
diff --git a/day03.py b/day03.py
new file mode 100644
index 0000000..39a2d6e
--- /dev/null
+++ b/day03.py
@@ -0,0 +1,99 @@
+from collections import defaultdict
+from dataclasses import dataclass
+from functools import reduce
+from typing import Any, Optional
+from aoc import Aoc
+
+
+@dataclass
+class Number:
+    value: int
+    symbol: Optional[tuple[int, int, str]]
+    startx: int
+    endx: int
+    linenr: int
+
+
+class Day03(Aoc[list[Number]]):
+    def __init__(self) -> None:
+        super().__init__(2023, 3)
+
+    def get_symbol(
+        self, inpt: list[str], startx: int, endx: int, liney: int
+    ) -> Optional[tuple[int, int, str]]:
+        symbol = None
+        for x in range(max(0, startx - 1), min(len(inpt[0]), endx + 1)):
+            yrange = [liney - 1, liney, liney + 1]
+            if x != startx - 1 and x != endx:
+                yrange.remove(liney)
+            if liney == 0:
+                yrange.remove(liney - 1)
+            if liney == len(inpt) - 1:
+                yrange.remove(liney + 1)
+            for y in yrange:
+                try:
+                    if inpt[y][x] != "." and not inpt[y][x].isnumeric():
+                        symbol = (x, y, inpt[y][x])
+                except IndexError:
+                    pass
+        return symbol
+
+    def parseinput(self, inpt: str) -> list[Number]:
+        numbers = []
+        lines = inpt.splitlines()
+        for posy, line in enumerate(lines):
+            num_accum = None
+            firstx = 0
+            lastx = 0
+            for posx, char in enumerate(line):
+                if char.isnumeric():
+                    if num_accum is None:
+                        num_accum = char
+                        firstx = posx
+                    else:
+                        num_accum += char
+                else:
+                    if num_accum is not None:
+                        lastx = posx
+                        symbol = self.get_symbol(lines, firstx, lastx, posy)
+                        numbers.append(
+                            Number(int(num_accum), symbol, firstx, lastx, posy)
+                        )
+
+                        num_accum = None
+                        firstx = 0
+                        lastx = 0
+
+            if num_accum is not None:
+                lastx = len(line)
+                symbol = self.get_symbol(lines, firstx, lastx, posy)
+                numbers.append(Number(int(num_accum), symbol, firstx, lastx, posy))
+
+                num_accum = None
+                firstx = 0
+                lastx = 0
+
+        return numbers
+
+    def part1(self, inpt: list[Number]) -> int:
+        return sum([number.value for number in inpt if number.symbol is not None])
+
+    def part2(self, inpt: list[Number]) -> Any:
+        gears_to_number = defaultdict(list)
+        for number in inpt:
+            if number.symbol is not None and number.symbol[2] == "*":
+                gears_to_number[number.symbol].append(number.value)
+        return sum(
+            reduce(lambda x, y: x * y, numbers)
+            for numbers in gears_to_number.values()
+            if len(numbers) == 2
+        )
+
+
+def main() -> None:
+    day03 = Day03()
+    day03.run()
+
+
+if __name__ == "__main__":
+    main()