Fill in a number in the □ of the number "25□79, so that this number can be divisible by 11, how much should be filled in the box.
在"25□79这个数的□内填上一个数字，使这个数能被11整除，方格内应填多少．
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">12 - 2 - 9</gadget>
<output>1</output>

<result>1</result>