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

Read also:

• What are the potential economic consequences of the U.S. following Europe's lead on climate policies, as discussed in the article?
• Why do women consider 80% of men as unattractive?
• Stellar Blade More Than Doubles Sony’s Previous Steam CCU Record for Single Player Games - Wccftech
• How come I can't stay sober?
• Is it possible for the AfD to ever win the chancellorship in Germany?
• What's an uncomfortable truth you've learned to accept?
• What do people aim for when they meditate, and how do they do it properly?
• What are some important works of Marcel Proust (novelist)?
• Why are white women dating more black guys than ever?
• Why do people love to live alone in a house?
• Can I know a love story of a medical student?