Five surgeons are discussing who makes the best patients to operate on.  The first surgeon says, "I like to see accountants on my operating table, because when you open them up, everything inside is numbered."

The second responds, "Yeah, but you should try electricians!  Everything inside them is color-coded."

The third surgeon says, "No, I really think file clerks are the best; everything inside them is in alphabetical order."

The fourth surgeon chimes in: "You know, I like construction workers.  Those guys always understand when you have a few parts left over at the end, and when the job takes longer than you said it would."

But the fifth surgeon shut them all up when he observed: "You're all wrong.  Politicians are the easiest to operate on.  There's no guts, no heart, and no spine, and the head and tail are interchangeable