update restrict possible usernames solution (#35973)

guide/english/certifications/javascript-algorithms-and-data-structures/regular-expressions/restrict-possible-usernames/index.md

@@ -6,21 +6,15 @@ title: Restrict Possible Usernames
 ## Solution:
 ```javascript
 let username = "JackOfAllTrades";
-let userCheck = /^[a-z]{2,}\d*$/i;
+const userCheck = /^[a-z]([0-9]{2,}|[a-z]+\d*)$/i;
 let result = userCheck.test(username);
 ```
 ## Explain:
-1. The only numbers in the username have to be at the end. `\d$`
-   There can be zero or more of them at the end. `*`
-```javascript
-/\d*$/;
-```
-2. Username letters can be lowercase and uppercase. `i`
-```javascript
-/\d*$/i;
-```
-3. Usernames have to be at least two characters long. `{2,}`
-   A two-letter username can only use alphabet letter characters. `^[a-z]`
-```javascript
-/^[a-z]{2,}\d*$/i;
-```
+1. `^` - start of input
+2. `[a-z]` - first character is a letter
+3. `[0-9]{2,0}` - ends with two or more numbers
+4. `|` - or
+5. `[a-z]+` - has one or more letters next
+6. `\d*` - and ends with zero or more numbers
+7. `$` - end of input
+8. `i` - ignore case of input