To build a road, the repaired length is 3/7 of the unrepaired length, and the repaired length is 800 meters less than the unrepaired length. How many meters is the total length of this road?
修一条公路，已修长度是未修长度的(3/7)，已修的长度比未修的长度少800米，这条公路全长多少米？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">800 / (4/7)</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 - 800</gadget>
<output>600</output>

<gadget id="calculator">600 + 1_400</gadget>
<output>2_000</output>

<result>2_000</result>