请使用Kruskal算法求出下图的最小生成树，依次写出每次被选择的合法的合并代价最小的边的编号，用一个空格分隔（如果同时存在多条边满足要求，选择编号最小的）。顶点a到顶点b（a＜b）之间的边编号为ab，例如图中权值为1的边编号为45。 Please use Kruskal algorithm for the following graph to find the minimum spanning tree. Write down the edge labels which are selected in the minimum spanning tree one by one （if there are multiple valid edges, select the vertex with the minimum label). The label of an edge connecting vertex a and vertex b is ab （a＜b). For ex