Distribute 12 cards to A, B, C, and D, 3 cards for each person. The cards are divided into three types. The red card is worth 5 points, the green card is worth 2 points, and the yellow card is worth 1 point. As a result, A gets 6 points, B gets 11 points, and C gets 9 points. It is known that the number of red cards is the same as that of yellow cards, so how many points does D get.
将12张卡片分给甲、乙、丙、丁4个人，每人3张，卡片分三种，红卡片值是5分、绿卡片值是2分、黄卡片值是1分，结果甲得6分，乙得11分，丙得9分，已知红卡片的张数与黄卡片相同，那么丁得到多少分．
<gadget id="calculator">1 * 1</gadget>
<output>1</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<result>4</result>