1 files changed, 1 insertions, 1 deletions
diff --git a/Day3.lean b/Day3.lean
index 00ef709..ae9cd2d 100644
--- a/Day3.lean
+++ b/Day3.lean
@@ -92,7 +92,7 @@ def parse (schematic : String) : Except String Schematic := do
 def part1 (schematic : Schematic) : Nat :=
   -- fast lookup: We need to know if a part is at a given coordinate
   open Std(HashSet) in
-  let partCoordinates := HashSet.insertMany HashSet.empty $ schematic.parts.map Part.position
+  let partCoordinates := HashSet.insertMany HashSet.emptyWithCapacity $ schematic.parts.map Part.position
   let partNumbers := schematic.numbers.filter λnumber ↦
     number.positions.any λposition ↦
       position.adjacents.any partCoordinates.contains