Hongxing Village planted 35 trees last year, and this year planted 20 poplars and 17 willows. How many more trees are planted this year than last year?
红星村去年栽树35棵，今年又栽了20棵杨树和17棵柳树，今年栽的树比去年栽的树多多少棵？
<gadget id="calculator">17 - 35</gadget>
<output>-18</output>

<gadget id="calculator">20 + (-18)</gadget>
<output>2</output>

<result>2</result>