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

Read also:

• Older Americans are happiest living in these 5 US states, study says — is yours one of them? - Yahoo
• How do flat Earthers explain the existence of other spherical planets?
• How does the narcissist react when he realizes you no longer care?
• Are fanservice-y characters (i.e. Lara Croft, Tifa Lockhart) immediately bad?
• Why do foolish atheists think their strange delusional theories are facts?
• Al Pacino Meets Pope Leo XIV, Becoming First Movie Star to Get an Audience With American Pontiff - The Hollywood Reporter
• Why do people stay in cults after they have joined?
• Why do some people admire Latin American cultures but not want to be from or live in those countries?
• Why aren't there any Indian girls married to Chinese guys but Chinese girls married to Indian guys?
• What is a good tool for product analytics besides Google Analytics?