The railway from Zhengzhou to Beijing is 689 kilometers long, and the railway from Beijing to Tianjin is 137 kilometers long. How many kilometers does it take to travel from Zhengzhou to Tianjin via Beijing by train?
郑州到北京的铁路长689千米，北京到天津的铁路长137千米．从郑州出发，乘火车途经北京到达天津，共要行多少千米？
<gadget id="calculator">689 + 137</gadget>
<output>826</output>

<result>826</result>