To build a road, 20% of the total length was repaired on the first day, and 35% of the total length was repaired on the second day, and 450 meters remained unrepaired. How long is this road in meters?
修一条公路，第一天修了全长的20%，第二天修了全长的35%，还剩450米没有修，这条路长多少米？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">1 - (1/5) - (7/20)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">450 / (9/20)</gadget>
<output>1_000</output>

<result>1_000</result>