I like engineers

Five surgeons are taking a coffee break.
1st surgeon says: “Accountants are the best to operate on because when you open them up, everything inside is numbered.
2nd surgeon says: “Nah, librarians are the best. Everything inside them is in alphabetical order.”
3rd surgeon says: “Try electricians, man! Everything inside THEM is colour coded.”
4th surgeon says: “I prefer lawyers. They’re heartless, spineless, gutless and their heads and their butts are interchangeable.”
To which the 5th surgeon, who has been quietly listening to the conversation, says

“I like engineers....they always understand when you have a few parts left over at the end.”