Wenfeng Great World is promoting a "Blue Cat" schoolbag during the summer vacation. Members can enjoy a discount of 18 yuan on top of the half price. As a result, Xiaohua's mother bought this schoolbag with a membership card of 72 yuan. How much is the original price of the schoolbag?
文峰大世界暑假促销一款"蓝猫"书包，会员可以在半价的基础上再优惠18元．结果小华妈妈用会员卡72元买下了这款书包，书包原价多少元？
<gadget id="calculator">72 + 18</gadget>
<output>90</output>

<gadget id="calculator">90 * 2</gadget>
<output>180</output>

<result>180</result>