There are 19 black swans, and the number of white swans is 9 times more than that of black swans. How many white swans are there?
黑天鹅有19只，白天鹅的只数比黑天鹅的3倍多9只．白天鹅有多少只？
<gadget id="calculator">19 * 3</gadget>
<output>57</output>

<gadget id="calculator">57 + 9</gadget>
<output>66</output>

<result>66</result>