Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to protect your server from hackers [title] Invest on a firewall. [step] After establishing your server, the next immediate thing you need to do is to put up a firewall. Firewalls are programs the filter out the information that goes in and out of your computer.

Ending1: [substeps] There are a lot of firewall applications available on the internet and from local computer stores, but even the less experienced hackers can get past these. Invest on a well-developed and reputable application to ensure utmost security. Ending2: Doing so will make it easier for hackers to access your emails and messages. Also, keep in mind that this is a somewhat technical process. Ending3: People using many firewalls are paid to use their firewall. An internet firewall is perhaps a better option if you are looking for protection for video surveillance, for example! [title] Install removable hardware. Ending4: To create a firewall on your server, you need to place firewall panels on top of it. Each firewall panel will contain a different type of information.

Answer format: ending1/ending2/ending3/ending4