There are 45 apple trees and pear trees in the orchard, among which there is a pear tree, how many more apple trees than pear trees.
果园里有苹果树和梨树共45棵，其中梨树有a棵，苹果树比梨树多多少棵．
<gadget id="calculator">45 - 2</gadget>
<output>43</output>

<result>43</result>