B"You are given an undirected unweighted connected graph consisting of n vertices and m edges. It is guaranteed that there are no self-loops or multiple edges in the given graph. Your task is to choose at most lfloor frac{n}{2} rfloor vertices in this graph so each unchosen vertex is adjacent (in other words, connected by an edge) to at least one of chosen vertices. It is guaranteed that the answer exists. If there are multiple answers, you can print any. You will be given multiple independent queries to answer. The first line contains a single integer t ( 1 <= t <= 2 cdot 10^5 ) -- the number of queries. Then t queries follow. The first line of each query contains two integers n and m ( 2 <= n <= 2 cdot 10^5 , n - 1 <= m <= min(2 cdot 10^5, frac{n(n-1)}{2}) ) -- the number of vertices and the number of edges, respectively. The following m lines denote edges: edge i is represented by a pair of integers v_i , u_i ( 1 <= v_i, u_i <= n , u_i ne v_i ), which are the indices of vertices connected by the edge. There are no self-loops or multiple edges in the given graph, i. xe2 x80 x89e. for each pair ( v_i, u_i ) there are no other pairs ( v_i, u_i ) or ( u_i, v_i ) in the list of edges, and for each pair ( v_i, u_i ) the condition v_i ne u_i is satisfied. It is guaranteed that the given graph is connected. It is guaranteed that sum m <= 2 cdot 10^5 over all queries. For each query print two lines. In the first line print k ( 1 <= lfloor frac{n}{2} rfloor ) -- the number of chosen vertices. In the second line print k distinct integers c_1, c_2, ... , c_k in any order, where c_i is the index of the i -th chosen vertex. It is guaranteed that the answer exists. If there are multiple answers, you can print any. In the first query any vertex or any pair of vertices will suffice. Note that you don't have to m"...