The number of A is 15 less than the number of B, and the number of B is 28. What is the sum of the two numbers of A and B?
甲数比乙数少15，乙数是28，甲乙两数的和是多少．
<gadget id="calculator">28 - 15</gadget>
<output>13</output>

<gadget id="calculator">13 + 28</gadget>
<output>41</output>

<result>41</result>