(2/5)<(7/(△))<(1/2), what is the sum of all integers that can be filled in △.
(2/5)＜(7/(△))＜(1/2)，△中可以填写的所有的整数的和是多少．
<gadget id="calculator">15 + 16 + 17</gadget>
<output>48</output>

<result>48</result>