ߣߐ߰ߦߊ߬ߓߟߏߡߊ߬ ߝߋ߲߫ u ߦߋ߫ ߞߊ߬ ߦߌߟߡߊߦߊ߫ ߦߙߌߞߊ߫ ߘߊ߲ߠߌ߲ߜߍ ߓߍ߯ ߘߐ߫ ߡߍ߲ ߘߌ߫ ߓߍ߲߬ ߸ ߝߙߋߞߋߓߐߢߊ ߘߊ߲߬ߓߊߟߌ߫ ߓߏ߲ߞߣߐ ߘߌ߫ ߛߋ߫ ߛߌ߲ߘߌ߫ ߟߊ߫ ߏ߬ ߘߐ߫ (x1, y1) ߢߊߓߐߟߌ߫ ߞߋߟߋ߲߫  ߘߐ߫.