Xiao Ming and Xiao Gang each have several glass marbles. Xiao Ming said to Xiao Gang: "If I give you two, we have the same number of glass marbles." Xiao Gang said: "If I give you two, your marbles will be equal." The number of balls will be three times that of mine." How many glass marbles do Xiao Ming and Xiao Gang have?
小明和小刚各有玻璃弹球若干个，小明对小刚说："我若给你两个，我们的玻璃弹球一样多．"小刚说："我若给你两个，你的弹球数量将是我的3倍．"小明和小刚共有玻璃弹球多少个？
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">12 + 6 + 2</gadget>
<output>20</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 - 4</gadget>
<output>6</output>

<gadget id="calculator">10 + 6</gadget>
<output>16</output>

<result>16</result>