Fill in the numbers according to the law: 4, 9, 16, 25, how much, 49.
按规律填数：4，9，16，25，多少，49．
<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<result>36</result>