There are 20 seats in a row in the auditorium. Xiaofang and Xiaoying are going to sit together, and Xiaofang is on Xiaoying's left, how many different ways of sitting in this row?
礼堂里一排有20个座位．小芳和小英要坐在一起，并且小芳在小英的左边，在这一排有多少种不同的坐法？
<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<result>19</result>