A and B are going to explore in the desert. They walk 20 kilometers deep into the desert every day. It is known that each person can carry food and water for one person at most for 12 days. If some food is not allowed to be stored on the way, ask one of them How many kilometers can you go deep into the desert? (The last two people are required to return to the starting point)
A、B两人要在沙漠中探险，他们每天向沙漠深处走20千米，已知每人最多可以携带一个人12天的食物和水，如果不准部分食物存放于途中，问其中一人最远可以深入沙漠多少千米？(要求最后两个人都要返回出发点)
<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">8 * 20</gadget>
<output>160</output>

<result>160</result>