A professional household who raises rabbits wants to sell 538 rabbits. 168 were sold last month and 228 this month. How many rabbits are left in professional rabbit farmers?
一养兔专业户要出售兔子538只．上个月出售168只，本月出售228只．养兔专业户还剩多少只兔？
<gadget id="calculator">538 - 168 - 228</gadget>
<output>142</output>

<result>142</result>