Strict group rules 
* no one will remove anyone
* no one will chatting useless out of limit 
* no one will chatting more than 10 to 15 minutes 
* no one will fight and prank with anyone 
* who use dirty language and can be remove from this group
* everyone call up to 2 people
*  no one will make more than 5 admins
* no chatting during class