There are 45 passengers on the bus, 12 people get off at stop 1, and 19 people get on the bus, how many people are on the bus now?
公共车上有乘客45人，到1号站下车12人，又上车19人，现在车上有多少人？
<gadget id="calculator">45 - 12</gadget>
<output>33</output>

<gadget id="calculator">33 + 19</gadget>
<output>52</output>

<result>52</result>