The printing room of the school needs to copy 6 pieces of materials, both front and back. If at most 2 sheets can be copied at a time, how many copies are required at least.
学校文印室需要复印6张资料，正反面都要复印．如果一次最多能复印2张，至少需要复印多少次．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">6 * 1</gadget>
<output>6</output>

<result>6</result>