diff --git a/2018/d02/ex2/ex2.py b/2018/d02/ex2/ex2.py
new file mode 100755
index 0000000..fb60f27
--- /dev/null
+++ b/2018/d02/ex2/ex2.py
@@ -0,0 +1,26 @@
+#!/usr/bin/env python
+
+import itertools
+import sys
+
+
+def solve(input: str) -> str:
+    def find_box_ids(boxes: list[str]) -> str:
+        for lhs, rhs in itertools.combinations(boxes, 2):
+            assert len(lhs) == len(rhs)  # Sanity check
+            for i in range(len(lhs)):
+                if lhs[:i] == rhs[:i] and lhs[i + 1 :] == rhs[i + 1 :]:
+                    return lhs[:i] + lhs[i + 1 :]
+        assert False  # Sanity check
+
+    boxes = input.splitlines()
+    return find_box_ids(boxes)
+
+
+def main() -> None:
+    input = sys.stdin.read()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()