Observe a sequence of numbers: 3, 8, 13, 18, 23, 28, ..., according to this rule, what is the seventh number in this sequence.
观察一列数：3，8，13，18，23，28，…，按照这样规律，在此数列中第七个数是多少．
<gadget id="calculator">28 + 5</gadget>
<output>33</output>

<result>33</result>