Add consecutive natural numbers starting from 1, and miss a number due to carelessness when adding, the result is that the average of these numbers is 15.9, what is the missing number?
把从1开始的连续自然数相加，在加的时候由于粗心漏掉一个数，结果这些数的平均数是15.9，漏掉的这个数是多少？
<gadget id="calculator">1 + 31</gadget>
<output>32</output>

<gadget id="calculator">32 * 15</gadget>
<output>480</output>

<gadget id="calculator">480 + 16</gadget>
<output>496</output>

<gadget id="calculator">30 * 15.9</gadget>
<output>477</output>

<gadget id="calculator">496 - 477</gadget>
<output>19</output>

<result>19</result>