The ratio of A and B is 4:3, and the sum of their greatest common divisor and least common multiple is 520. What is A's number?
甲、乙两数的比是4：3，它们的最大公约数与最小公倍数的和是520，甲数是多少．
<gadget id="calculator">1 + 12</gadget>
<output>13</output>

<gadget id="calculator">520 / 13</gadget>
<output>40</output>

<gadget id="calculator">4 * 40</gadget>
<output>160</output>

<result>160</result>