diff --git a/draw.sh b/draw.sh
index 9293fe1..7449c81 100644
--- a/draw.sh
+++ b/draw.sh
@@ -31,7 +31,7 @@ else
 	for svg in "${1}"*.svg ; do
 		if [[ ${c} -lt ${2} ]]; then
 			echo $c
-			let "c=c+1"
+			c=$((c+1))
 			continue
 		fi
 		filename=`basename "${svg}"`
@@ -44,8 +44,8 @@ fi
 i=0
 #files in dir
 for svg in "${1}"*.svg ; do
-	if [[ "${2}" != "" ]] && [[ ${i} -lt ${2} ]]; then
-		let "i=i+1"
+	if [[ "${2}" != "" ]] && [[ ${2} -ne 0 ]] && [[ ${i} -lt ${2} ]]; then
+		i=$((i+1))
 		continue
 	fi 
 	filename=`basename "${svg}"`