There are two kinds of balls, A and B, in the box. The A ball is 3 times as many as the B ball and there are 2 balls. Each time, 7 B balls and 15 A balls are taken out of the box. After several times, there are still 3 B balls in the box, 53 If there is only ball A, how much more ball A than ball B in the box.
箱子里有甲乙两种球，甲球是乙球的3倍多2只，每次从箱子里取出7只乙球，15只甲球，若干次后，箱子里还剩3只乙球，53只甲球，则箱子里原有甲球比乙球多多少只．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">53 - 9 - 2</gadget>
<output>42</output>

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<gadget id="calculator">21 - 15</gadget>
<output>6</output>

<gadget id="calculator">42 / 6</gadget>
<output>7</output>

<gadget id="calculator">15 * 7</gadget>
<output>105</output>

<gadget id="calculator">7 * 7</gadget>
<output>49</output>

<gadget id="calculator">49 + 3</gadget>
<output>52</output>

<gadget id="calculator">53 - 52</gadget>
<output>1</output>

<gadget id="calculator">105 + 1</gadget>
<output>106</output>

<result>106</result>