diff --git a/day18.py b/day18.py
new file mode 100644
index 0000000..0927e50
--- /dev/null
+++ b/day18.py
@@ -0,0 +1,48 @@
+from tools.aoc import AOCDay
+from typing import Any
+
+
+class Day(AOCDay):
+    inputs = [
+        [
+            (38, "input18_test"),
+            (1926, "input18"),
+        ],
+        [
+            (19986699, "input18"),
+        ]
+    ]
+
+    def get_safe_tiles(self, rows: int) -> int:
+        row = self.getInput()
+        safe_tiles = row.count(".")
+        for _ in range(rows - 1):
+            row = "." + row + "."
+            new_row = ""
+            for i in range(1, len(row) - 1):
+                if row[i - 1] == '^' and row[i] == '^' and row[i + 1] == '.':
+                    new_row += "^"
+                elif row[i - 1] == '.' and row[i] == '^' and row[i + 1] == '^':
+                    new_row += "^"
+                elif row[i - 1] == '^' and row[i] == '.' and row[i + 1] == '.':
+                    new_row += "^"
+                elif row[i - 1] == '.' and row[i] == '.' and row[i + 1] == '^':
+                    new_row += "^"
+                else:
+                    new_row += "."
+
+            row = new_row
+            safe_tiles += row.count(".")
+
+        return safe_tiles
+
+    def part1(self) -> Any:
+        return self.get_safe_tiles(10 if self.is_test() else 40)
+
+    def part2(self) -> Any:
+        return self.get_safe_tiles(400_000)
+
+
+if __name__ == '__main__':
+    day = Day(2016, 18)
+    day.run(verbose=True)
diff --git a/inputs/input18 b/inputs/input18
new file mode 100644
index 0000000..19f6948
--- /dev/null
+++ b/inputs/input18
@@ -0,0 +1 @@
+^.^^^.^..^....^^....^^^^.^^.^...^^.^.^^.^^.^^..^.^...^.^..^.^^.^..^.....^^^.^.^^^..^^...^^^...^...^.
diff --git a/inputs/input18_test b/inputs/input18_test
new file mode 100644
index 0000000..235ef50
--- /dev/null
+++ b/inputs/input18_test
@@ -0,0 +1 @@
+.^^.^.^^^^
\ No newline at end of file