There is a rectangular vegetable field with a length of 40 meters and a width of 25 meters. If you want to fence it on three sides, what is the minimum length of the fence?
有一块长方形菜地长40米，宽25米，要在它的三面围上篱笆，最少要准备多长的篱笆？
<gadget id="calculator">2 * 25</gadget>
<output>50</output>

<gadget id="calculator">40 + 50</gadget>
<output>90</output>

<result>90</result>