There are 46 students in Class 1, 30 of whom can play the piano and 28 of them can play the violin. Then how many people in this class can play both the piano and the violin?
四1班有46人，其中会弹钢琴的有30人，会拉小提琴的有28人，则这个班既会弹钢琴又会拉小提琴的至少有多少人．
<gadget id="calculator">28 - 46</gadget>
<output>-18</output>

<gadget id="calculator">30 + (-18)</gadget>
<output>12</output>

<result>12</result>