10 students are lined up in a horizontal line, Xiao Li is the 6th from the left, Xiao Hong is the 9th from the right, how many students are there between Xiao Li and Xiao Hong?
10个同学排成一列横队，从左边数起小利是第6个，从右边起小红是第9个，小利和小红间隔多少个同学．
<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">10 - 9</gadget>
<output>1</output>

<gadget id="calculator">10 - 4 - 1 - 2</gadget>
<output>3</output>

<result>3</result>