diff --git a/13/01.sh b/13/01.sh
index 3b2ffc7..cc29c56 100755
--- a/13/01.sh
+++ b/13/01.sh
@@ -7,19 +7,19 @@ while read line; do
   if [[ $line == *','* ]]; then
     dots[$line]=1
   else
-    folds+=( $(sed 's/fold along //' <<< $line) )
+    folds+=( ${line#fold along } )
   fi
 done
 
 fold=${folds[0]}
-fold_axis=$(sed 's/=.*$//' <<< $fold)
-fold_coord=$(sed 's/^.*=//' <<< $fold)
+fold_axis=${fold%=*}
+fold_coord=${fold#*=}
 new_dots=()
 todel_dots=()
 
 for dot in ${!dots[@]}; do
-  dot_x=$(sed 's/,.*$//' <<< $dot)
-  dot_y=$(sed 's/^.*,//' <<< $dot)
+  dot_x=${dot%,*}
+  dot_y=${dot#*,}
   if [[ $fold_axis == 'x' ]]; then
     if [ $dot_x -gt $fold_coord ]; then
       new_dots+=( "$((fold_coord*2-dot_x)),$dot_y" )
diff --git a/13/02.sh b/13/02.sh
index 0538b35..45e0678 100755
--- a/13/02.sh
+++ b/13/02.sh
@@ -9,13 +9,13 @@ while read line; do
   if [[ $line == *','* ]]; then
     dots[$line]=1
   else
-    folds+=( $(sed 's/fold along //' <<< $line) )
+    folds+=( ${line#fold along } )
   fi
 done
 
 for fold in ${folds[@]}; do
-  fold_axis=$(sed 's/=.*$//' <<< $fold)
-  fold_coord=$(sed 's/^.*=//' <<< $fold)
+  fold_axis=${fold%=*}
+  fold_coord=${fold#*=}
   new_dots=()
   todel_dots=()
   
@@ -26,8 +26,8 @@ for fold in ${folds[@]}; do
   fi
 
   for dot in ${!dots[@]}; do
-    dot_x=$(sed 's/,.*$//' <<< $dot)
-    dot_y=$(sed 's/^.*,//' <<< $dot)
+    dot_x=${dot%,*}
+    dot_y=${dot#*,}
     if [[ $fold_axis == 'x' ]]; then
       if [ $dot_x -gt $fold_coord ]; then
         new_dots+=( "$((fold_coord*2-dot_x)),$dot_y" )