There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly n - 1 edges that connect the center node with every other node.

You are given a 2D integer array edges where each edges[i] = [ui, vi] indicates that there is an edge between the nodes ui and vi. Return the center of the given star graph.

Actually it doesn't seem like a medium problem.

You just need to see the edge[0][0] and edge[0][1] and remember those numbers.

And see next, if there are same number, that's the answer.

"""
1791. Find Center of Star Graph

There is an undirected star graph consisting of n nodes labeled from 1 to n.
A star graph is a graph where there is one center node and exactly n - 1 edges that connect the center node with every other node.

You are given a 2D integer array edges where each edges[i] = [ui, vi] indicates that there is an edge between the nodes ui and vi.
Return the center of the given star graph.

Input: edges = [[1,2],[2,3],[4,2]]
Output: 2
"""

edges = [[1,2],[5,1],[1,3],[1,4]]

num1 = edges[0][0]
num2 = edges[0][1]

if num1 == edges[1][0] or num1 == edges[1][1]:
    print(num1)
else:
    print(num2)