diff --git a/aoc/utils.go b/aoc/utils.go
index 0073787..da14b71 100644
--- a/aoc/utils.go
+++ b/aoc/utils.go
@@ -136,3 +136,25 @@ func (s *CustomScanner[T, K]) Scan() bool {
 func (s *CustomScanner[T, K]) Err() error {
 	return s.err
 }
+
+type numeric interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 |
+		~float32 | ~float64
+}
+
+func Sum[T numeric](s []T) T {
+	var res T
+	for _, t := range s {
+		res += t
+	}
+	return res
+}
+
+func Prod[T numeric](s []T) T {
+	var res = T(1)
+	for _, t := range s {
+		res *= t
+	}
+	return res
+}
diff --git a/year25/day6.go b/year25/day6.go
index af22264..556473b 100644
--- a/year25/day6.go
+++ b/year25/day6.go
@@ -3,17 +3,13 @@ package year25
 import (
 	"bytes"
 	"fmt"
-	"log"
-	"os"
 	"strconv"
 	"strings"
 
 	"git.bizdoc.ro/gabi-public/Advent-of-Code.git/aoc"
-	"git.bizdoc.ro/private/devkit.git/collections/geometry/v2"
 )
 
 func Day6Part1(c aoc.Context) (int64, error) {
-	c.Logger = log.New(os.Stdout, "", log.LstdFlags)
 	lines, tokens, err := day6ParseInputs(c)
 	if err != nil {
 		return 0, fmt.Errorf("error parsing inputs: %w", err)
@@ -48,7 +44,11 @@ func Day6Part2(c aoc.Context) (int64, error) {
 	for _, t := range tokens {
 		calc := day6NewCalc(t.Operation)
 
-		mask := geometry.NewGrid[byte](t.Size, len(lines)).Data()
+		mask := make([][]byte, t.Size)
+		for i := range t.Size {
+			mask[i] = make([]byte, len(lines))
+		}
+
 		for i := range mask {
 			for j := range mask[i] {
 				mask[i][j] = lines[j][t.Start+i]