There is a batch of flour in the grain depot, half of the total is shipped out for the first time, more than 3 tons, and the remaining half and 7 tons are shipped out for the second time, leaving 4 tons left. How many tons of flour are there in the grain depot?
粮库内有一批面粉，第一次运出总数的一半多3吨，第二次运出剩下的一半又7吨，还剩下4吨．问粮库里原有面粉多少吨？
<gadget id="calculator">4 + 7</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<gadget id="calculator">22 + 3</gadget>
<output>25</output>

<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<result>50</result>