KöMaL 2024 B5368

In a table tennis championship any two contestants played with each other exactly once. In each match, the winner got 1 point, and the loser got 0 points (there is no tie in table tennis). Interestingly, one contestant has won against exactly those who scored more than him in the championship and lost to exactly those who scored less than him in the championship. Find the smallest possible number of contestants participating in the championship. (It is possible that several contestants got the same score at the end of the championship. At least two contestants participated in the championship.)