diff --git a/src/holt59/aoc/2015/day15.py b/src/holt59/aoc/2015/day15.py
new file mode 100644
index 0000000..953dabf
--- /dev/null
+++ b/src/holt59/aoc/2015/day15.py
@@ -0,0 +1,57 @@
+import math
+import sys
+from typing import Sequence, cast
+
+import parse  # type: ignore
+
+
+def score(ingredients: list[list[int]], teaspoons: Sequence[int]) -> int:
+    return math.prod(
+        max(
+            0,
+            sum(
+                ingredient[prop] * teaspoon
+                for ingredient, teaspoon in zip(ingredients, teaspoons)
+            ),
+        )
+        for prop in range(len(ingredients[0]) - 1)
+    )
+
+
+lines = sys.stdin.read().splitlines()
+
+ingredients: list[list[int]] = []
+for line in lines:
+    _, *scores = cast(
+        tuple[str, int, int, int, int, int],
+        parse.parse(  # type: ignore
+            "{}: capacity {:d}, durability {:d}, flavor {:d}, "
+            "texture {:d}, calories {:d}",
+            line,
+        ),
+    )
+    ingredients.append(scores)
+
+total_teaspoons = 100
+calories: list[int] = []
+scores: list[int] = []
+
+for a in range(total_teaspoons + 1):
+    for b in range(total_teaspoons + 1 - a):
+        for c in range(total_teaspoons + 1 - a - b):
+            teaspoons = (a, b, c, total_teaspoons - a - b - c)
+
+            scores.append(score(ingredients, teaspoons))
+            calories.append(
+                sum(
+                    ingredient[-1] * teaspoon
+                    for ingredient, teaspoon in zip(ingredients, teaspoons)
+                )
+            )
+
+
+answer_1 = max(scores)
+print(f"answer 1 is {answer_1}")
+
+answer_2 = max(score for score, calory in zip(scores, calories) if calory == 500)
+print(f"answer 2 is {answer_2}")
diff --git a/src/holt59/aoc/inputs/holt59/2015/day15.txt b/src/holt59/aoc/inputs/holt59/2015/day15.txt
new file mode 100644
index 0000000..d1af06e
--- /dev/null
+++ b/src/holt59/aoc/inputs/holt59/2015/day15.txt
@@ -0,0 +1,4 @@
+Sugar: capacity 3, durability 0, flavor 0, texture -3, calories 2
+Sprinkles: capacity -3, durability 3, flavor 0, texture 0, calories 9
+Candy: capacity -1, durability 0, flavor 4, texture 0, calories 1
+Chocolate: capacity 0, durability 0, flavor -2, texture 2, calories 8
diff --git a/src/holt59/aoc/inputs/tests/2015/day15.txt b/src/holt59/aoc/inputs/tests/2015/day15.txt
new file mode 100644
index 0000000..1a7ff25
--- /dev/null
+++ b/src/holt59/aoc/inputs/tests/2015/day15.txt
@@ -0,0 +1,2 @@
+Butterscotch: capacity -1, durability -2, flavor 6, texture 3, calories 8
+Cinnamon: capacity 2, durability 3, flavor -2, texture -1, calories 3