There was a number riddle at the party, and the answer was an 8-digit number. Guessed: □54□7□39, the host reminded: "Among the 8-digit numbers without repeating numbers, the smallest number is 2." To guess this riddle, how many times do you have to guess at most?
联欢会上有一则数字谜语，谜底是一个8位数．现已猜出：□54□7□39，主持人提示："这个无重复数字的8位数中，最小的数字是2．"要猜出这个谜语，最多还要猜多少次．
<gadget id="calculator">3 * 2 * 1</gadget>
<output>6</output>

<result>6</result>