CodeIgniter with Multiple Sites

in htaccess I'm write

DirectoryIndex index.php
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ ./index.php?/$1 [L,QSA]
RewriteRule ^(.*)$ ./subdomains/accounts/index.php?/$1 [L,QSA]