What is the sum of X+XX+XXX+XXXX?

Read also:

• Why do I have the impression that almost all questions about advertising the flat Earth theory come from people who don't believe in a flat Earth themselves and are just provoking?
• Do you think Andrew Tate and Nigel Farage are part of a "similar phenomenon"?
• What's the most valuable lesson you've learned in life, and how has it impacted your journey so far?
• New Apple study challenges whether AI models truly “reason” through problems - Ars Technica
• Is Elon Musk an actual genius, or is he surrounded by people smarter than him?
• Inbox: This will be a tough roster to crack - Green Bay Packers
• What are the advantages of using plastic straws over metal or glass straws when drinking carbonated beverages? Is there a noticeable difference in taste?
• Skyrim fans baffled after finding huge gold hoard we’ve never seen before - GAMINGbible
• A hidden swarm of 'city-killer' asteroids around Venus could one day collide with Earth, simulations suggest. - Farmingdale Observer
• Why is my ex mad I moved on when he dumped me?