There are two piles of grain, of which the first pile accounts for 65% of the total amount of the two piles of grain. If 120 kilograms are taken from the first pile to the second pile, the two piles of grain are exactly equal. How many kilograms was the first pile of grain originally?
有两堆粮食，其中第一堆占两堆粮食总数的65%．如果从第一堆拿出120千克到第二堆，则两堆粮食正好相等．第一堆粮食原有多少千克？
<gadget id="calculator">65 / 100</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">1 - (13/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(13/20) - (7/20)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">2 / (3/10)</gadget>
<output>20/3 = around 6.666667</output>

<gadget id="calculator">120 * (20/3) * (13/20)</gadget>
<output>520</output>

<result>520</result>