Question: To put a fitted sheet on the bed
Option 0: slip four of the fitted ends over the ends of the mattress, then pull the forth end of the mattress up bending it toward the center of the mattress somewhat, slip the fitted sheet off it and let it go.
Option 1: slip three of the fitted ends over the ends of the mattress, then pull the forth end of the mattress up bending it toward the center of the mattress somewhat, slip the fitted sheet over it and let it go.
Answer: 1