There are n teams numbered from $0$ to n $- 1$ participating in a tournament.

You are given a $2 {D}$ integer array edges of length m, where each edges[i] = [u, v] represents a directed edge indicating that team u is stronger than team v. A team a is considered a champion if there is no team b that is stronger than team a.

Return the team that is the champion if there is a unique champion. If there is no unique champion, return $-1$.

Constraints:

• $1 \leq$ n $\leq 100$

• m $==$ edges.length

• $0 \leq$ m $\leq$ n $\times$ ( n $- 1) / 2$

• edges[i].length $== 2$

• $0 \leq$ edges[i][j] $\leq$ n $- 1$

• edges[i][0] $\neq$ edges[i][1]

• The input is generated such that if team a is stronger than team b, team b is not stronger than team a.

• The input is generated such that if team a is stronger than team b and team b is stronger than team c, then team a is stronger than team c.

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.