If a number in a natural number is equal to the sum of all other numbers, such a number is called "S number", (for example: 561, 6=5+1), then the largest three-digit "S number" is the same as the smallest What is the difference between the three-digit "S number" of
若一个自然数中的某个数字等于其它所有数字之和，则称这样的数为"S数"，(例：561，6=5+1)，则最大的三位数"S数"与最小的三位数"S数"之差为多少．
<gadget id="calculator">990 - 101</gadget>
<output>889</output>

<result>889</result>