Let a, b, and c be the numbers in 0-9 respectively, and they are not all 0 and 9 at the same time, and the decimal 0 will be repeated. {_{a}**(•)}b{_{c} After **(•)} is transformed into the simplest fraction, how many different cases are there in the molecule?
设a、b、c分别是0-9中的数字，它们不同时都为0也不同时都为9，将循环小数0.{_{a}**(•)}b{_{c}**(•)}化成最简分数后，分子有多少不同情况．
<gadget id="calculator">9 * 111</gadget>
<output>999</output>

<gadget id="calculator">999 - 333</gadget>
<output>666</output>

<gadget id="calculator">999 / 37</gadget>
<output>27</output>

<gadget id="calculator">666 - 27</gadget>
<output>639</output>

<gadget id="calculator">639 + 9</gadget>
<output>648</output>

<gadget id="calculator">648 + 12</gadget>
<output>660</output>

<result>660</result>