How many different four-digit numbers can be formed with the four numbers 0, 3, 5, 7, and 9?
用0，3，5，7，9其中的四个数字能组成多少个不同的四位数．
<gadget id="calculator">4 * 4 * 3 * 2</gadget>
<output>96</output>

<result>96</result>