Find the Town Judge

Problem Statement:

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



Solution:
class Solution:
    def findJudge(self, N: int, trust: List[List[int]]) -> int:
        dict={}
        li=[0]*(N+1)
        for i,j in trust:
            dict[i]=j
            li[j]+=1
        
        for i in range(1,len(li)):
            if li[i]>=(N-1) and i not in dict:
                return i
        return -1