diff --git a/2024/day/25/part/1/solve copy.ts b/2024/day/25/part/1/solve copy.ts
new file mode 100644
index 0000000..4be765c
--- /dev/null
+++ b/2024/day/25/part/1/solve copy.ts	
@@ -0,0 +1,29 @@
+export default function solve(input: string) {
+  const locks: number[][] = [];
+  const keys: number[][] = [];
+  for (const lines of input.split("\n\n")) {
+    const rows = lines.split("\n").slice(1, -1);
+    const heights = Array.from(rows[0], () => 0);
+    if (lines.startsWith(".")) rows.reverse();
+    for (let x = 0; x < rows[0].length; x++) {
+      for (let height = rows.length; height > 0; height--) {
+        if (rows[height - 1][x] === ".") continue;
+        heights[x] = height;
+        break;
+      }
+    }
+    if (lines.startsWith("#")) locks.push(heights);
+    else keys.push(heights);
+  }
+  let count = 0;
+  for (const lock of locks) {
+    for (const key of keys) {
+      if (
+        key.every((height, index, { length: max }) =>
+          height + lock[index] <= max
+        )
+      ) count++;
+    }
+  }
+  return count;
+}
diff --git a/2024/day/25/part/1/solve.test.ts b/2024/day/25/part/1/solve.test.ts
new file mode 100644
index 0000000..f6bfcb1
--- /dev/null
+++ b/2024/day/25/part/1/solve.test.ts
@@ -0,0 +1,48 @@
+import solve from "./solve.ts";
+
+import { assertEquals } from "@std/assert";
+
+Deno.test("example", () => {
+  const input = `\
+#####
+.####
+.####
+.####
+.#.#.
+.#...
+.....
+
+#####
+##.##
+.#.##
+...##
+...#.
+...#.
+.....
+
+.....
+#....
+#....
+#...#
+#.#.#
+#.###
+#####
+
+.....
+.....
+#.#..
+###..
+###.#
+###.#
+#####
+
+.....
+.....
+.....
+#....
+#.#..
+#.#.#
+#####`;
+
+  assertEquals(solve(input), 3);
+});
diff --git a/2024/day/25/part/1/solve.ts b/2024/day/25/part/1/solve.ts
new file mode 100644
index 0000000..e6b89aa
--- /dev/null
+++ b/2024/day/25/part/1/solve.ts
@@ -0,0 +1,19 @@
+export default function solve(input: string, { size = 5 } = {}) {
+  const locks: number[][] = [];
+  const keys: number[][] = [];
+  for (const schematic of input.split("\n\n")) {
+    const rows = schematic.split("\n").slice(1, -1);
+    const heights = Array.from(
+      { length: size },
+      (_, x) => rows.reduce((height, row) => height + +(row[x] === "#"), 0),
+    );
+    (schematic[0] === "#" ? locks : keys).push(heights);
+  }
+  let count = 0;
+  for (const lock of locks) {
+    for (const key of keys) {
+      if (key.every((height, index) => height + lock[index] <= size)) count++;
+    }
+  }
+  return count;
+}