There are 20 people who want to go to the other side of the river. There is only one boat by the river, and there can only be 5 people on the boat at a time. How many times must the boat carry at least to allow them all to cross the river.
有20个人要到河的对岸去，河边只有一条船，船上每次只能坐5个人，小船至少要载多少次才能让他们全部过河．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>