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

Read also:

• Why do atheists love to preach against Abrahamic religions and mock God? Even if they do not fear the eternal fire of hell, pious Muslims will certainly not leave them alone and will take brutal revenge until they surrender and repent of their sins.
• How does the narcissist react when he realizes you no longer care?
• Should you have a threesome with your best friend and your significant other if the significant other requests it?
• Is there a type of function where every point has exactly one tangent line passing through it? If yes, what is this type of function called?
• Do you want to have an XXX chat?
• What baseball stories from the early days of the sport seem too bizarre to be true?
• Were Dalits prohibited from drinking water from wells in ancient times? Is there any evidence to support this claim?
• Reality TV star’s son dead at 16: ‘Life is so cruel and unfair’ - AL.com
• France blown away! Records sent tumbling as Les Bleus concede five goals for the first time in 56 YEARS against incredible Spain - Goal.com
• What is the nastiest thing you had your wife do and she loved it?