A train from Beijing to Shanghai has traveled the whole distance (3/7). At this time, it is still 56 kilometers away from the midpoint. How many meters is the whole journey?
一列火车从北京开往上海，已经行了全程的(3/7)，这时距中点还有56千米，全程多少米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(1/2) - (3/7)</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">56 / (1/14)</gadget>
<output>784</output>

<gadget id="calculator">784 * 1_000</gadget>
<output>784_000</output>

<result>784_000</result>