$\textbf{Tournament}$
A tournament has $2020$ participants. In each round, two people are paired and the winner advances to the next round. No game will end up with a tie. If in any round, there is an odd number of participants, the one without a paired opponent will automatically advance to the next round. The tournament will continue till the champion is declared. How many matches will this tournament have?
$\textbf{Answer}$
$2019$.
$\textbf{Analysis}$
Each match eliminates one participant. A total of $2019$ participants need to be eliminated before the champion can be declared. Therefore, $2019$ matches are required.
$\textbf{Note}$
It is a brain teaser, not a math test problem. Therefore, a quick solution should exist despite that it is possible to get the same answer by performing somewhat lengthy calculation.