abc represents a three-digit number with different digits. If the sum of these three numbers is 6, then such a three-digit number is called a "lucky number". How many "lucky numbers" are there in the three-digit number?
abc表示一个各位数字互不相同的三位数，若这三个数字和是6，则称这样三位数为"幸运数"，三位数中"幸运数"有多少个．
<result>24</result>