Divide the six numbers 33, 51, 65, 77, 85, and 91 into two groups, each group has three numbers, so that the products of the two groups are equal, what is the difference between the sum of the two groups of numbers?
把33，51，65，77，85，91六个数分为两组，每组三个数，使两组的积相等，则这两组数之和的差为多少．
<gadget id="calculator">33 + 91 + 85</gadget>
<output>209</output>

<gadget id="calculator">51 + 65 + 77</gadget>
<output>193</output>

<gadget id="calculator">209 - 193</gadget>
<output>16</output>

<result>16</result>