When the Red Scarf Spring Festival condolence team decided on the program list for the nursing home performance, they encountered the following problems: the performance on New Year’s Eve included singing, dancing, acrobatics, and sketches. 3 items, acrobatics are not ranked in the second item, and sketches are not ranked in the first item. Then, how many different arrangements are there for the program list that meets the above requirements?
红领巾春节慰问小组在确定去敬老院演出的节目单时，遇到如下问题：除夕夜的演出有唱歌、舞蹈、杂技、小品4个节目，如果要求唱歌不排在第4项，舞蹈不排在第3项，杂技不排在第2项，小品不排在第1项．那么，满足上述要求的节目单，共有多少种不同的排法．
<gadget id="calculator">3 * 3 * 1 * 1</gadget>
<output>9</output>

<result>9</result>