pile of coal, after 345 kg was used on the first day, 422 kg was transported in again, and 559 kg was used on the second day, and there was no surplus. How many kilograms did the pile of coal originally have?
一堆煤，第一天用去345千克后，又运进422千克，第二天用去559千克，没有剩余，这堆煤原来有多少千克．
<gadget id="calculator">559 - 422</gadget>
<output>137</output>

<gadget id="calculator">345 + 137</gadget>
<output>482</output>

<result>482</result>