There are many desks in the classroom, all neatly arranged, the number of desks in each column is equal, and the number of desks in each row is equal. Xiaoqiu's desk is the third from the front, and the fourth from the back. There are three on his left. There is 1 picture on the right, how many pictures are there in Xiaoqiu's classroom?
教室里有很多桌子，都整齐地排列着，每列桌子数相等，每排的桌子数相等，小秋的桌从前面数第3张，从后面数第4张，他的左边有3张，右边有1张，小秋的教室一共有多少张？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 + 3</gadget>
<output>6</output>

<gadget id="calculator">3 + 1 + 1</gadget>
<output>5</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<result>30</result>