In a town of `n` people labeled `1` to `n`, there may be a **town judge**. The judge trusts nobody, everybody (except the judge) trusts the judge, and there is exactly one such person.
Given `trust` where `trust[i] = [a, b]` means person `a` trusts person `b`, return the judge's label, or `-1` if there is no judge.
Example 1
Input:n = 2, trust = [[1,2]]
Output:2
Explanation:Person 2 is trusted by 1 and trusts no one.
Example 2
Input:n = 3, trust = [[1,3],[2,3],[3,1]]
Output:-1
Explanation:Person 3 trusts someone, so cannot be the judge.
Constraints
- 1 <= n <= 1000
- 0 <= trust.length <= 10^4
- All trust pairs are unique