nginx: [emerg] "server" directive is not allowed here

I have reconfigured nginx but i can't get it to restart using the following config: conf:

server {
   listen 80;
   server_name www.example.com;
   return 301 $scheme://example.com$request_uri;
}


server {
   listen 80;
   server_name example.com;

   access_log /var/log/nginx/access.log;
   error_log  /var/log/nginx/error.log;

   location /robots.txt {
       alias /path/to/robots.txt;
       access_log off;
       log_not_found off;
   }

   location = /favicon.ico { access_log off; log_not_found off; }

   location / {
      proxy_pass_header Server;
      proxy_set_header Host $http_host;
      proxy_redirect off;
          proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Scheme $scheme;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_connect_timeout 30;
      proxy_read_timeout 30;
      proxy_pass http://127.0.0.1:8000;
   }

   location /static {
      expires 1M;
      alias  /path/to/staticfiles;
   }
}

after running sudo nginx -c conf -t to test the configuration the following error is returned i can't figure out what is really the problem

nginx: [emerg] "server" directive is not allowed here in    /etc/nginx/sites-available/config:1
nginx: configuration file /etc/nginx/sites-available/config test failed