It is known that a, b, and c are all prime numbers, and a*(b+c)=27, then what is the sum of the three numbers a, b, and c?
已知a、b、c都是质数，并且a*(b+c)=27，那么a、b、c三个数的和是多少？
<gadget id="calculator">3 + 2 + 7</gadget>
<output>12</output>

<result>12</result>