The students do exercises. Xiaolei stands on the 3rd row from the left and the 8th row from the right; the 6th from the front and the 7th from the back. If there are the same number of students in each row, how many students do exercises in total?
同学们做操．小雷站在左起第3行，右起第8行；从前面数是第6个，从后边数是第7个．如果每行的人数一样多，共有多少名同学做操？
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">12 * 10</gadget>
<output>120</output>

<result>120</result>