From city A to city B, (4/5) are flat roads, and the rest are uphill and downhill. A car goes back and forth between cities A and B, traveling a total of 5 kilometers uphill. What is the distance in miles from city A to city B?
从A城到B城，其中(4/5)是平路，其余的上坡路和下坡路．一辆汽车从A、B两城往返一趟，共行5千米上坡路．A城到B城的距离多少千米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 / (1/5)</gadget>
<output>25</output>

<result>25</result>