It’s simple: the finalists from the previous tournament start from the second round:p.
P.S. But seriously, we could have drawn lots for 14 players, and a little later, the 15th and 16th (the ones who joined) would play against each other.
So far, 11 people have paid the entry fee. We don’t have a quorum yet. We need to wait for at least the 12th person to pay so we can start the tournament.

