There are 10 male students lined up in a row, and a female student is inserted between every two male students. How many female students are there in total?
有10名男同学排成一排，在每两名男同学之间插入一名女同学，女同学一共有几名？
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<result>9</result>