There are 6 classes in the fifth grade of Guangming Primary School. There will be a tug-of-war competition (single cycle). How many games will there be in total?
光明小学五年级有6个班，要举行拔河比赛(单循环)，一共要赛几场？
<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<result>15</result>