28 people participate in a table tennis match, using knockout matches, how many matches are needed to determine the champion.
28人参加乒乓球比赛，采用淘汰赛，要决出冠军，共要比赛多少场．
<gadget id="calculator">14 + 7 + 3 + 2 + 1</gadget>
<output>27</output>

<result>27</result>