In this problem, a tree is an undirected graph that is connected and has no cycles.
You are given a graph that started as a tree with n nodes labeled 1 to n, with one additional edge added. The added edge has two different vertices chosen from 1 to n, and was not an edge that already existed.
Return an edge that can be removed so that the resulting graph is a tree. If there are multiple answers, return the edge that occurs last in the input.
Example 1:
Input: 3 1 2 1 3 2 3 Output: 2 3
Example 2:
Input: 4 1 2 2 3 3 4 1 4 2 4 Output: 2 4
Input format: First line: n. Next n lines: edges.
Output format: The redundant edge.