how to block excluding specific url in nginx?

[goversation]

hi. i have a trouble and question!
my current configuration in nginx is like ..
only "/blah/" url can access..

================================
server {
    location / {
             return 403;
    }
    location ^~ /blah/ {
             proxy_pass http://127.0.0.1:8888;
    }
}
================================

but now i have to access "/" location, too
how to block excluding specific url in nginx?

to conclude,
i want to access the only "/" and "/blah/" (for example, aaa.com and
aaa.com/blah/~~)

can anyone help me?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,255147,255147#msg-255147