The Yangtze River is 6,300 kilometers long, which is 900 kilometers longer than the Yellow River. How many kilometers long is the Yellow River?
长江全长6300千米，比黄河长900千米，黄河全长几千米？
<gadget id="calculator">6_300 - 900</gadget>
<output>5_400</output>

<result>5_400</result>