For a bottle of fruit juice, half of all the juice was drunk for the first time, 50 ml less, and half of the remaining juice was drunk for the second time, 25 ml more. At this time, there were 125 ml left in the bottle. How many milliliters is this bottle of juice?
一瓶果汁，第一次喝了所有果汁的一半少50毫升，第二次喝了剩下果汁的一半多25毫升，这时瓶中还剩125毫升．这瓶果汁原有多少毫升？
<gadget id="calculator">125 + 25</gadget>
<output>150</output>

<gadget id="calculator">150 * 2</gadget>
<output>300</output>

<gadget id="calculator">300 - 50</gadget>
<output>250</output>

<gadget id="calculator">250 * 2</gadget>
<output>500</output>

<result>500</result>