Two — one to screw it most of the way in and the other to give it a surprise twist at the end.
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Drinking, bathing, washing, swimming, etc.
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To hide in a bag of M&M's.
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Three. One to climb the ladder while the second kicks the ladder out from under her. And the third to say, "I knew that was too high for you dear."
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Just one, provided there is a programmer around to explain how to do it.
or