public class Solution
extends Object
997 - Find the Town Judge\.
Easy
In a town, there are `n` people labeled from `1` to `n`. There is a rumor that one of these people is secretly the town judge.
If the town judge exists, then:
1. The town judge trusts nobody.
2. Everybody (except for the town judge) trusts the town judge.
3. There is exactly one person that satisfies properties **1** and **2**.
You are given an array `trust` where trust[i] = [ai, bi] representing that the person labeled ai trusts the person labeled bi.
Return _the label of the town judge if the town judge exists and can be identified, or return_ `-1` _otherwise_.
**Example 1:**
**Input:** n = 2, trust = \[\[1,2]]
**Output:** 2
**Example 2:**
**Input:** n = 3, trust = \[\[1,3],[2,3]]
**Output:** 3
**Example 3:**
**Input:** n = 3, trust = \[\[1,3],[2,3],[3,1]]
**Output:** -1
**Constraints:**
* `1 <= n <= 1000`
* 0 <= trust.length <= 104
* `trust[i].length == 2`
* All the pairs of `trust` are **unique**.
* ai != bi
* 1 <= ai, bi <= n