The engineering team repaired a section of road, and when the full length (3/5) was repaired, it had exceeded the midpoint of 400 meters. How long is this road in meters?
工程队修一段公路，当修好全长的(3/5)时，已超过中点400米．这段公路全长多少米？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">400 / (1/10)</gadget>
<output>4_000</output>

<result>4_000</result>