There is a sequence, 4, 10, 16, 22, ... 70, how many items are there in this sequence.
有一个数列，4、10、16、22、…70，这个数列共有多少项．
<gadget id="calculator">70 - 4</gadget>
<output>66</output>

<gadget id="calculator">10 - 4</gadget>
<output>6</output>

<gadget id="calculator">66 / 6</gadget>
<output>11</output>

<gadget id="calculator">11 + 1</gadget>
<output>12</output>

<result>12</result>