A rectangular lawn is 30 meters long and 15 meters wide. One side is against a wall, and the other three sides are surrounded by fences. What is the minimum meter of the fence?
一块长方形草地，长30米，宽15米，一边靠墙，其余三边围上篱笆，篱笆最少要多少米？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">30 + 30</gadget>
<output>60</output>

<result>60</result>