When a number is divided by 4, the quotient and remainder are both 3, what is the dividend?
一个数除以4，商和余数都是3，被除数是多少．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

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

<result>15</result>