The school holds a Go competition for teachers and staff. There are 8 players participating. Every two players have to play a game of Go. How many games are there in total?
学校举办教工围棋比赛，有8名选手参加，每两人之间要下一局棋，一共要多少局．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<result>28</result>