diff --git a/days/src/main/kotlin/Day16.kt b/days/src/main/kotlin/Day16.kt
index a2c9814..268cede 100644
--- a/days/src/main/kotlin/Day16.kt
+++ b/days/src/main/kotlin/Day16.kt
@@ -4,9 +4,11 @@ import be.vandewalleh.aoc.utils.input.Day
 import be.vandewalleh.aoc.utils.input.Groups
 import be.vandewalleh.aoc.utils.input.Input
 import be.vandewalleh.aoc.utils.input.createDay
+import org.eclipse.collections.api.multimap.list.ListMultimap
 import org.eclipse.collections.api.multimap.list.MutableListMultimap
 import org.eclipse.collections.api.multimap.set.MutableSetMultimap
 import org.eclipse.collections.impl.factory.Multimaps
+import org.eclipse.collections.impl.multimap.list.FastListMultimap
 
 @Day(16)
 class Day16(@Groups val input: Input<List<List<String>>>) {
@@ -67,7 +69,6 @@ class Day16(@Groups val input: Input<List<List<String>>>) {
                 mult *= myTicketValues[index]
             }
         }
-
         return mult
     }
 
@@ -76,7 +77,7 @@ class Day16(@Groups val input: Input<List<List<String>>>) {
         val queue = ArrayDeque<Int>()
 
         indexesByCategory.multiValuesView()
-            .sortedBy { it.size() }
+            .toSortedListBy { it.size() }
             .forEach { it.forEach { if (toBeRemoved.add(it)) queue.add(it) } }
 
         queue.removeLast()
@@ -100,8 +101,8 @@ class Day16(@Groups val input: Input<List<List<String>>>) {
     }
 
     private fun indexesByCategory(
-        rangesByName: MutableListMultimap<String, IntRange>,
-        validTickets: MutableList<List<Int>>,
+        rangesByName: ListMultimap<String, IntRange>,
+        validTickets: List<List<Int>>,
     ): MutableSetMultimap<String, Int> {
         val indexesByCategory = Multimaps.mutable.set.empty<String, Int>()
 
@@ -110,21 +111,26 @@ class Day16(@Groups val input: Input<List<List<String>>>) {
             val ranges = entry.two.toList()
 
             for (i in validTickets.first().indices) {
-                val allInRange = validTickets
-                    .asSequence()
-                    .map { it[i] }
-                    .all { inRanges(it, ranges) }
+                var allInRange = true
+                for(ticket in validTickets){
+                    val current = ticket[i]
+                    if(!inRanges(current, ranges)){
+                        allInRange = false
+                        break
+                    }
+                }
                 if (allInRange) indexesByCategory.put(category, i)
             }
         }
         return indexesByCategory
     }
 
-    private fun validTickets(rangesByName: MutableListMultimap<String, IntRange>): MutableList<List<Int>> {
+    private fun validTickets(rangesByName: MutableListMultimap<String, IntRange>): List<List<Int>> {
         val validTickets = mutableListOf<List<Int>>()
+        val ranges = rangesByName.valuesView().toList()
         for (line in nearbyTicketsGroup) {
-            val ticket = line.splitToSequence(",").map { it.toInt() }.toList()
-            if (isTicketValid(ticket, rangesByName.valuesView().toList())) {
+            val ticket = line.split(",").map { it.toInt() }
+            if (isTicketValid(ticket, ranges)) {
                 validTickets.add(ticket)
             }
         }
@@ -132,7 +138,7 @@ class Day16(@Groups val input: Input<List<List<String>>>) {
     }
 
     private fun namedRanges(): MutableListMultimap<String, IntRange> {
-        val rangesByName = Multimaps.mutable.list.empty<String, IntRange>()
+        val rangesByName = FastListMultimap<String, IntRange>()
         for (line in rangesGroup) {
             val name = line.substringBefore(":")
             extractRanges(line).forEach {
diff --git a/days/src/test/kotlin/Day16Benchmark.kt b/days/src/test/kotlin/Day16Benchmark.kt
index ac60bf0..41288d8 100644
--- a/days/src/test/kotlin/Day16Benchmark.kt
+++ b/days/src/test/kotlin/Day16Benchmark.kt
@@ -10,7 +10,7 @@ import org.openjdk.jmh.runner.options.OptionsBuilder
 
 /*
 Benchmark             Mode  Cnt  Score   Error  Units
-Day16Benchmark.part2  avgt    5  1.748 ± 0.047  ms/op
+Day16Benchmark.part2  avgt    5  0.697 ± 0.026  ms/op
 */
 
 @BenchmarkMode(Mode.AverageTime)