diff --git a/2023/day15.py b/2023/day15.py
new file mode 100644
index 0000000..903a1de
--- /dev/null
+++ b/2023/day15.py
@@ -0,0 +1,46 @@
+import fileinput
+from collections import defaultdict
+
+
+def HASH(code):
+    val = 0
+    for c in code:
+        val += ord(c)
+        val *= 17
+        val %= 256
+    return val
+
+
+# Parse problem input.
+STEPS = next(fileinput.input()).strip().split(',')
+
+# Solve part 1.
+print("Part 1:", sum(HASH(step) for step in STEPS))
+
+# Solve part 2.
+BOXES = defaultdict(list)
+
+for step in STEPS:
+    if step[-1] == '-':
+        label = step[:-1]
+        box = HASH(label)
+        BOXES[box] = [lens for lens in BOXES[box] if lens[0] != label]
+
+    else:
+        focal = int(step[-1])
+        label = step[:-2]
+        box = HASH(label)
+
+        for i, (other_label, other_focal) in enumerate(BOXES[box]):
+            if other_label == label:
+                BOXES[box][i] = (label, focal)
+                break
+        else:
+            BOXES[box].append((label, focal))
+
+lenses = {}
+for box_num, box in BOXES.items():
+    for slot_num, (label, focal) in enumerate(box, start=1):
+        lenses[label] = (box_num + 1) * slot_num * focal
+
+print("Part 2:", sum(lenses.values()))