Arrange 108, 1008, 10008, 100008, ..., 100...08 together in turn to form a natural number 108100810008100008...100...08 that can be divisible by 81. What is the minimum sum of this number?
将108、1008、10008、100008、…、100…08依次排在一起组成一个能被81整除的自然数108100810008100008…100…08，这个数的数字和至少是多少．
<gadget id="calculator">1 + 8 + 1 + 8 + 1 + 8 + 1 + 8</gadget>
<output>36</output>

<result>36</result>