people play table tennis singles. If it is a knockout match (two people compete, the loser will withdraw from the match, and the winner will compete with others), how many games will be played to determine the champion? [Hint: 8 people were divided into two groups to compete, and 4 people won. These 4 people were divided into two groups to compete again, and two of them won again. The final will be held to determine the champion]
8个人进行乒乓球单打比赛．如果是淘汰赛(两个人进行比赛，输的退出不再比赛，赢的再与其他人比赛)，决出冠军一共要进行多少场比赛？【提示：8个人分两人一组进行比赛，结果4人赢了．这4人又分两人一组比赛，又有两人赢了．再进行决赛，决出冠军】
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<result>7</result>