So I solved this problem called El Fucho and honestly the statement looks scarier than the actual logic. It talks about winners’ group, losers’ group, pairing, odd/even teams, dropping down… feels like some complex sports league. But the funny part? The whole tournament can be explained using just one formula: 2n − 2 Basically it's double elimination only like,,

Every team starts in the winners' group like: “Yesss we are undefeated, life is good.” Then they lose once and immediately: “Welcome to the losers’ group, enjoy your stay.” Lose again and: “Pack your bags bro, you're OUT.” So yeah — every eliminated team eats exactly 2 L’s. No more, no less. CF gods decided.

“But bro… the FINAL???”

CF statement: “When one team is left in each group, they play ONE final match.” You might think there’s some cool twist here. Nope That final match is literally just: Losers’ bracket guy getting smacked with his second loss....( I thought might end up infinite loop ) , but yeah that was the main catch , kinda liked the question.. So it’s already counted in our 2n − 2. Nothing extra. No bonus DLC match. Game over.

No simulations. No trees. No graphs. No stress. Just one line: cout << 2*n — 2; And you’re done .....

CF writers wrote a whole football anime backstory for a one-line formula And honestly, I kinda liked it.. (:D)