There are 54 students in a class electing the monitor. The candidates are A, B, C, and three. From then on, how many votes must A have at least to be elected.
某班54名同学选举班长，候选人是甲、乙、丙、三人，得票最多的人当选，在开票中途统计时，甲得15票，乙得12票，丙得8票．此后甲最少还要得多少票才能当选．
<gadget id="calculator">15 + 12 + 8</gadget>
<output>35</output>

<gadget id="calculator">54 - 35</gadget>
<output>19</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">19 - 3</gadget>
<output>16</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<result>9</result>