diff --git a/day11/day11.py b/day11/day11.py
new file mode 100755
index 0000000..ca7c69c
--- /dev/null
+++ b/day11/day11.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+import sys
+from typing import Sequence, Tuple, Set
+from copy import deepcopy
+
+
+Point = Tuple[int, int]
+
+
+class Grid:
+    def __init__(self, grid: Sequence[Sequence[int]]):
+        self.grid = grid
+        self.rows = len(grid)
+        self.cols = len(grid[0]) if self.rows else 0
+
+    def neighbors(self, point: Point) -> Set[Point]:
+        i, j = point
+        return {
+            (r, c)
+            for r, c in [
+                (i - 1, j - 1),
+                (i - 1, j + 1),
+                (i + 1, j - 1),
+                (i + 1, j + 1),
+                (i, j - 1),
+                (i, j + 1),
+                (i - 1, j),
+                (i + 1, j),
+            ]
+            if 0 <= r < self.rows and 0 <= c < self.cols
+        }
+
+    def step(self):
+        # Add 1 to everything
+        for i in range(self.rows):
+            for j in range(self.cols):
+                self.grid[i][j] += 1
+
+        # "Apply" grid - increments to add to each grid item
+        apply = [[0 for _ in row] for row in self.grid]
+        flashed = [[False for _ in row] for row in self.grid]
+
+        while True:
+            changed = False
+
+            for i in range(self.rows):
+                for j in range(self.cols):
+                    if self.grid[i][j] > 9 and not flashed[i][j]:
+                        flashed[i][j] = True
+                        changed = True
+                        for ni, nj in self.neighbors((i, j)):
+                            self.grid[ni][nj] += 1
+
+            if not changed:
+                break
+        # Now, reset anything greater than 9 to 0
+        for i in range(self.rows):
+            for j in range(self.cols):
+                if self.grid[i][j] > 9:
+                    self.grid[i][j] = 0
+
+    def __getitem__(self, key: Point) -> int:
+        r, c = key
+        return self.grid[r][c]
+
+    def __str__(self) -> str:
+        lines = []
+        for row in self.grid:
+            line = ""
+            for col in row:
+                if col == 0:
+                    line += "\u001b[34;1m0\u001b[0m"
+                else:
+                    line += str(col)
+            lines += [line]
+        return "\n".join(lines)
+
+
+grid = Grid([[int(c) for c in line.strip()] for line in sys.stdin])
+
+
+def part1(grid: Grid):
+    flashes = 0
+    for step in range(100):
+        grid.step()
+        for row in grid.grid:
+            for col in row:
+                if col == 0:
+                    flashes += 1
+    print(flashes)
+
+
+def part2(grid: Grid):
+    steps = 0
+    while any(any(col != 0 for col in row) for row in grid.grid):
+        grid.step()
+        steps += 1
+    print(steps)
+
+
+print("Part 1")
+part1(deepcopy(grid))
+print("Part 2")
+part2(grid)
diff --git a/day11/example.txt b/day11/example.txt
new file mode 100644
index 0000000..a3819c9
--- /dev/null
+++ b/day11/example.txt
@@ -0,0 +1,10 @@
+5483143223
+2745854711
+5264556173
+6141336146
+6357385478
+4167524645
+2176841721
+6882881134
+4846848554
+5283751526
\ No newline at end of file
diff --git a/day11/example2.txt b/day11/example2.txt
new file mode 100644
index 0000000..e282ad7
--- /dev/null
+++ b/day11/example2.txt
@@ -0,0 +1,5 @@
+11111
+19991
+19191
+19991
+11111
\ No newline at end of file
diff --git a/day11/input.txt b/day11/input.txt
new file mode 100644
index 0000000..555e530
--- /dev/null
+++ b/day11/input.txt
@@ -0,0 +1,10 @@
+8826876714
+3127787238
+8182852861
+4655371483
+3864551365
+1878253581
+8317422437
+1517254266
+2621124761
+3473331514
\ No newline at end of file