title: NGINX add two variable/arguments numbers
body: <p>I'm trying to set up an Nginx, where I want to add two numbers together.</p>
  <pre><code>server {
          server_name &quot;~^pr-(\d*).review-apps.example.com$&quot;;
          
          location / {
              set $port 50000+$1;
              proxy_pass &quot;http://localhost:$port/test&quot;;
          }
      } 
  </code></pre>
  <p>But this doesn't work . (Result is in string. For example &quot;50000+125&quot;)</p>
  <p>How can I add two numbers in nginx.conf? Is it even possible?</p>