In the four □ of 17□17□17□17□17, fill in one operation symbol "+", "-", "*" and "/". What is the maximum value of the resulting formula.
在17□17□17□17□17的四个□中填入"+"、"-"、"*"、"/"运算符号各一个．所成的算式的最大值是多少．
<gadget id="calculator">17 * 17</gadget>
<output>289</output>

<gadget id="calculator">17 / 17</gadget>
<output>1</output>

<gadget id="calculator">17 - 1</gadget>
<output>16</output>

<gadget id="calculator">289 + 16</gadget>
<output>305</output>

<result>305</result>