Topic: install wordpress inside rails on heroku

I unzip and rename wp-config-sample.php => wp-config.php and conffig it.
it is exactly my file (i have no edit)

// Heroku Postgres settings

if (isset($_ENV["DATABASE_URL"])) {

  $db = parse_url($_ENV["DATABASE_URL"]);

  define("DB_NAME", trim($db["path"],"/"));

  define("DB_USER", $db["user"]);

  define("DB_PASSWORD", $db["pass"]);

  define("DB_HOST", $db["host"]);

} else {

  die("Cannot determine database settings from DATABASE_URL\n");

}

Then I create .htaccess (app/.htaccess) and config(i have no edit):

<IfModule mod_rewrite.c> 
RewriteEngine On 
RewriteBase /blog/ 
RewriteRule ^index\.php$ - [L] 
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteRule . /blog/index.php [L] 
</IfModule> 

Then I upload it to blog folder on heroku. And try install but it always return eror 404 (I see logs heroku) my link to install:           
                 http://mywebsite.heroku.com/blog/wp-admin/install.php

ActionController::RoutingError (No route matches "/blog/wp-admin/install.php

Please help me install this.
Thanks so much