□/△=15…15, □What is the minimum.
□/△=15…15，□最小是多少．
<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<gadget id="calculator">15 * 16</gadget>
<output>240</output>

<gadget id="calculator">240 + 15</gadget>
<output>255</output>

<result>255</result>