In a town, there are N people labelled from 1 to N. There is a rumor that one of these people is secretly the town judge.
If the town judge exists, then:
- The town judge trusts nobody.
- Everybody (except for the town judge) trusts the town judge.
- There is exactly one person that satisfies properties 1 and 2.
You are given trust, an array of pairs trust[i] = [a, b] representing that the person labelled a trusts the person labelled b.
If the town judge exists and can be identified, return the label of the town judge. Otherwise, return -1.
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
Example 4:
Input: N = 3, trust = [[1,2],[2,3]] Output: -1
Example 5:
Input: N = 4, trust = [[1,3],[1,4],[2,3],[2,4],[4,3]] Output: 3
Constraints:
1 <= N <= 10000 <= trust.length <= 10^4trust[i].length == 2trust[i]are all differenttrust[i][0] != trust[i][1]1 <= trust[i][0], trust[i][1] <= N