diff --git a/aoc/src/dev/ctsk/aoc/days/Day11.scala b/aoc/src/dev/ctsk/aoc/days/Day11.scala
index f459fdd..01b6dde 100644
--- a/aoc/src/dev/ctsk/aoc/days/Day11.scala
+++ b/aoc/src/dev/ctsk/aoc/days/Day11.scala
@@ -11,26 +11,28 @@ object Day11 extends Solver(11):
       val mod = Math.pow(10, numDigits / 2).toLong
       Some(n % mod, n / mod)
 
-  private val memo = MuMap.empty[(Long, Int), Long]
-  private def count(initial: Long, numBlinks: Int): Long =
-    def rec(stone: Long, blinks: Int): Long =
-      if blinks == 0 then return 1L
-      memo.getOrElseUpdate(
-        (stone, blinks), {
-          if stone == 0 then rec(1L, blinks - 1)
-          else
-            halves(stone) match
-              case Some(a, b) =>
-                rec(a, blinks - 1) + rec(b, blinks - 1)
-              case None => rec(stone * 2024, blinks - 1)
-        }
-      )
-    rec(initial, numBlinks)
+  private def count(initial: Seq[Long], depth: Int): Long =
+    def step(stones: MuMap[Long, Long]): MuMap[Long, Long] =
+      val next = MuMap.empty[Long, Long].withDefaultValue(0L)
+      for ((stone, count) <- stones) {
+        if stone == 0 then next(1) += count
+        else
+          halves(stone) match
+            case Some((a, b)) =>
+              next(a) += count
+              next(b) += count
+            case None =>
+              next(stone * 2024) += count
+      }
+      next
+
+    val initMap = MuMap.from(initial.map((_, 1L)))
+    Seq.iterate(initMap, depth + 1)(step).last.values.sum
 
   def run(input: os.ReadablePath): (Timings, Solution) =
     val (pre_time, in) = timed { longs(os.read.lines(input).head) }
-    val (p1_time, p1_solution) = timed { in.map(v => count(v, 25)).sum }
-    val (p2_time, p2_solution) = timed { in.map(v => count(v, 75)).sum }
+    val (p1_time, p1_solution) = timed { count(in, 25) }
+    val (p2_time, p2_solution) = timed { count(in, 75) }
 
     (
       Timings(pre_time, p1_time, p2_time),