There are 30 seats in a row in the theater. Xiao Ming and Xiao Hong are going to watch a movie. They want to sit together, and Xiao Hong sits on Xiao Ming's left. How many different ways of sitting are there?
影院里一排座位有30个，小明和小红两人去看电影，他们要坐在一起，并且小红坐在小明的左边，一共有多少种不同的坐法．
<gadget id="calculator">30 - 1</gadget>
<output>29</output>

<result>29</result>