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

Read also:

• How should the government address the housing crisis in London that has affected people like 75-year-old Susan Curtis?
• Can you name a song with the word 'why' in it?
• Confirmed: Breakfast Cereals Are Getting Sweeter And Less Nutritious - ScienceAlert
• A Sleep Expert Says It's OK To Use Your Phone In Bed For A Surprising Reason - Bustle
• Stock Market Today: Dow up over 200 points, S&P 500 and Nasdaq back in positive territory as oil drops after Iran launches missiles at U.S. base in Qatar - MarketWatch
• When was the last time you had sex with someone much older than yourself?
• Mars Orbiter Captures Rare View of Ancient Volcano Poking Above the Clouds - Gizmodo
• Scientists develop 'mosquito STD' to combat malaria - Phys.org
• With 2 petawatts, the powerful American ZEUS laser competes with particle accelerators. - Farmingdale Observer
• CDC Health Advisory Says This 'Ongoing Risk' Leaves Travelers Vulnerable on Planes, Trains, Public Transport, and More - Travel + Leisure
• Has the time come for Ukraine to come to terms with Russia since the situation on the battlefield is clearly hopeless at this point?