To build a road, after 5 days of repairing, it will exceed the midpoint by 80 meters, and the rest will continue to be repaired at the original speed. It can be completed in 4 days. How long is the total length of this road?
修一条公路，修了5天后超过中点80米，剩下的按原来的速度继续修，4天可以完成，这条公路全长多少米？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

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

<gadget id="calculator">(5/9) - (1/2)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">80 / (1/18)</gadget>
<output>1_440</output>

<result>1_440</result>