Dad wants to plant willows around a square pond, one at each of the four vertices, and 25 on each side. How many willows does Dad need to plant in total?
爸爸要在一个正方形池塘四周种柳树，四个顶点各一棵，每边25棵，爸爸一共需要种多少棵柳树？
<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">100 - 4</gadget>
<output>96</output>

<result>96</result>