Fill in the numbers according to the law: 4, 7, 13, 25, how much, 97.
按规律填数：4，7，13，25，多少，97．
<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<gadget id="calculator">50 - 1</gadget>
<output>49</output>

<result>49</result>