Find the Town Judge

Statement

There are n people numbered from $1$ to n in a town. There's a rumor that one of these people is secretly the town judge. If there is a town judge, they must meet these conditions:

There are n people numbered from $1$ to n in a town. There’s a rumor that one of these people is secretly the town judge. A town judge must meet the following conditions:

• The judge doesn’t trust anyone.

• Everyone else (except the judge) trusts the judge.

• Only one person in the town can meet both of these conditions.

Given there is n and a two-dimensional array called trust,  each element trust[i] has two elements $[a_i,b_i]$, it means that a trusts person b. If there is a judge, return their number, return $-1$ otherwise.

Constraints:

• $1 \leq$n $\leq 1000$

• $0 \leq$trust.length $\leq 10^{4}$

• trust[i].length $== 2$

• ai $\ne$ bi

• $1 \leq$ai , bi $\leq$n

• All the pairs in trust are unique.

Examples