There are arrays (1, 1, 1), (2, 4, 8), (3, 9, 27), ..., then what is the sum of the last two digits of the sum of the three numbers in the 1998th group.
有数组(1，1，1)，(2，4，8)，(3，9，27)，…，那么第1998组的三个数之和的末两位数字之和是多少．
<result>13</result>