There are 45 students in the sixth grade, each of whom subscribes to at least one publication. Those who subscribed to "Extracurricular Life" (2/3), and those who subscribed to "Fun Mathematics" (3/5). How many people subscribe to both publications?
六年级共有45人，每人至少订一种刊物．订《课外生活》的有(2/3)，订《趣味数学》的有(3/5)．两种刊物都订的有多少人？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">45 * (2/3)</gadget>
<output>30</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">45 * (3/5)</gadget>
<output>27</output>

<gadget id="calculator">27 - 45</gadget>
<output>-18</output>

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

<result>12</result>