diff --git a/aoc2023/day14/main.go b/aoc2023/day14/main.go
index 1d1d135..963d2d2 100644
--- a/aoc2023/day14/main.go
+++ b/aoc2023/day14/main.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	_ "embed"
 	"fmt"
+	"slices"
 	"strings"
 
 	aoc "go.sour.is/advent-of-code"
@@ -62,7 +63,7 @@ func run(scan *bufio.Scanner) (*result, error) {
 					func(i int, v int, counts [3]int) [3]int {
 						counts[v]++
 						return counts
-					}, [3]int{}, maps.Values(memo)...)
+					}, [3]int{}, slices.Values(maps.Values(memo)))
 
 				// fmt.Println(i, counts)
 				i = 1_000_000_000 - (1_000_000_000-counts[0]-counts[1])%counts[2]
diff --git a/aoc2023/day15/main.go b/aoc2023/day15/main.go
index fa35168..14365df 100644
--- a/aoc2023/day15/main.go
+++ b/aoc2023/day15/main.go
@@ -32,14 +32,14 @@ func run(scan *bufio.Scanner) (*result, error) {
 		r.valuePT1 = aoc.Reduce(func(i int, t string, sum int) int {
 			sum += hash(t)
 			return sum
-		}, 0, ops...)
+		}, 0, slices.Values(ops))
 	}
 
 	var boxen boxes
 
 	boxen = aoc.Reduce(func(i int, op string, b boxes) boxes {
 		return b.Op(op)
-	}, boxen, ops...)
+	}, boxen, slices.Values(ops))
 
 	r.valuePT2 = boxen.Sum()
 
diff --git a/itertools.go b/itertools.go
index 6736518..3631055 100644
--- a/itertools.go
+++ b/itertools.go
@@ -1,6 +1,7 @@
 package aoc
 
 import (
+	"iter"
 	"strconv"
 )
 
@@ -17,8 +18,8 @@ func Repeat[T any](s T, i int) []T {
 	return lis
 }
 
-func Reduce[T, U any](fn func(int, T, U) U, u U, list ...T) U {
-	for i, t := range list {
+func Reduce[T, U any](fn func(int, T, U) U, u U, list iter.Seq[T]) U {
+	for i, t := range Enumerate(list) {
 		u = fn(i, t, u)
 	}
 	return u
@@ -54,3 +55,14 @@ func Pairwise[T any](arr []T) [][2]T {
 	}
 	return pairs
 }
+
+func Enumerate[T any](arr iter.Seq[T]) iter.Seq2[int, T] {
+	return func(yield func(int, T) bool) {
+		i := 0
+		for v := range arr {
+			if !yield(i, v) {
+				return
+			}
+		}
+	}
+}