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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