diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 8dbc517..c10e400 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -4,9 +4,7 @@
     <option name="autoReloadType" value="ALL" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="d5f54382-616d-41b2-b8f9-53d04e37d644" name="Changes" comment="init">
-      <change afterPath="$PROJECT_DIR$/go.mod" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/thousands.go" afterDir="false" />
+    <list default="true" id="d5f54382-616d-41b2-b8f9-53d04e37d644" name="Changes" comment="first version">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
@@ -54,7 +52,8 @@
   </component>
   <component name="VcsManagerConfiguration">
     <MESSAGE value="init" />
-    <option name="LAST_COMMIT_MESSAGE" value="init" />
+    <MESSAGE value="first version" />
+    <option name="LAST_COMMIT_MESSAGE" value="first version" />
   </component>
   <component name="VgoProject">
     <settings-migrated>true</settings-migrated>
diff --git a/thousands.go b/thousands.go
index dbb434a..28c3c8c 100644
--- a/thousands.go
+++ b/thousands.go
@@ -30,30 +30,29 @@ func Separate(Number interface{}, language ...string) (string, error) {
 	case "de":
 
 		formattedNumber = strings.ReplaceAll(formattedNumber, ",", ".")
-		numberLength := len(formattedNumber)
 
 		dec := ""
 
 		if strings.Index(formattedNumber, ".") != -1 {
-			dec = formattedNumber[strings.Index(formattedNumber, ".")+1 : numberLength]
+			dec = formattedNumber[strings.Index(formattedNumber, ".")+1 : len(formattedNumber)]
 			formattedNumber = formattedNumber[0:strings.Index(formattedNumber, ".")]
 
 		}
 
-		for i := 0; i <= numberLength; i = i + 4 {
+		for i := 0; i <= len(formattedNumber); i = i + 4 {
 
-			a := formattedNumber[0 : numberLength-i]
-			b := formattedNumber[numberLength-i : numberLength]
+			a := formattedNumber[0 : len(formattedNumber)-i]
+			b := formattedNumber[len(formattedNumber)-i : len(formattedNumber)]
 			formattedNumber = a + "." + b
 
 		}
 
 		if formattedNumber[0:1] == "." {
-			formattedNumber = formattedNumber[1:numberLength]
+			formattedNumber = formattedNumber[1:len(formattedNumber)]
 		}
 
-		if formattedNumber[numberLength-1:numberLength] == "." {
-			formattedNumber = formattedNumber[0 : numberLength-1]
+		if formattedNumber[len(formattedNumber)-1:len(formattedNumber)] == "." {
+			formattedNumber = formattedNumber[0 : len(formattedNumber)-1]
 		}
 
 		if dec != "" {
@@ -65,30 +64,29 @@ func Separate(Number interface{}, language ...string) (string, error) {
 	case "en":
 
 		formattedNumber = strings.ReplaceAll(formattedNumber, ",", "")
-		numberLength := len(formattedNumber)
 
 		dec := ""
 
 		if strings.Index(formattedNumber, ".") != -1 {
-			dec = formattedNumber[strings.Index(formattedNumber, ".")+1 : numberLength]
+			dec = formattedNumber[strings.Index(formattedNumber, ".")+1 : len(formattedNumber)]
 			formattedNumber = formattedNumber[0:strings.Index(formattedNumber, ".")]
 
 		}
 
-		for i := 0; i <= numberLength; i = i + 4 {
+		for i := 0; i <= len(formattedNumber); i = i + 4 {
 
-			a := formattedNumber[0 : numberLength-i]
-			b := formattedNumber[numberLength-i : numberLength]
+			a := formattedNumber[0 : len(formattedNumber)-i]
+			b := formattedNumber[len(formattedNumber)-i : len(formattedNumber)]
 			formattedNumber = a + "," + b
 
 		}
 
 		if formattedNumber[0:1] == "," {
-			formattedNumber = formattedNumber[1:numberLength]
+			formattedNumber = formattedNumber[1:len(formattedNumber)]
 		}
 
-		if formattedNumber[numberLength-1:numberLength] == "," {
-			formattedNumber = formattedNumber[0 : numberLength-1]
+		if formattedNumber[len(formattedNumber)-1:len(formattedNumber)] == "," {
+			formattedNumber = formattedNumber[0 : len(formattedNumber)-1]
 		}
 
 		if dec != "" {