A bus bound for Sanhui from Qucheng had 27 people on board when it left the station, 12 people got off the bus and 19 people got on the bus. How many people were in the bus when it arrived at the station?
一辆从渠城开往三汇的大客车出站时车上共坐有27人，在途中下车12人，上车19人．这辆大客车到站时车上共坐有多少人？
<gadget id="calculator">27 - 12</gadget>
<output>15</output>

<gadget id="calculator">15 + 19</gadget>
<output>34</output>

<result>34</result>