This year is 2010, Dongdong is 9 years old, and Dongdong's age is three times the age of his younger brother. So how many years, Dongdong's age is twice the age of his younger brother.
今年是2010年，冬冬9岁，冬冬的年龄是弟弟年龄的3倍．那么多少年，冬冬年龄是弟弟年龄的2倍．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">9 / 3 / 1</gadget>
<output>3</output>

<gadget id="calculator">9 / 3</gadget>
<output>3</output>

<gadget id="calculator">9 - 3 - 3</gadget>
<output>3</output>

<gadget id="calculator">2_010 + 3</gadget>
<output>2_013</output>

<result>2_013</result>