server {
    listen       81;
    server_name  _;

    root   /usr/share/nginx/html/demo;
    index  index.html index.htm;
    autoindex off;

    location ~ /(latest|[3-9+]\.[0-9])(/.*)? {
        try_files $2 $2/index.html =404;
    }

    location / {
       root   /usr/share/nginx/html/demo;      
    }


    error_page  404               /404.html;
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }
}