static void MainF(string[] args)
        {
#if false
            Reader = new StreamReader(@"Graph\MST\test\test.txt");
#else
            Reader = new StreamReader(Console.OpenStandardInput());
#endif
            t = ReadInt();

            for (int i = 0; i < t; i++)
            {
                ns = ReadIntArray();
                n  = ns[0];
                m  = ns[1];

                dis = new double[n, n];
                for (int k = 0; k < n; k++)
                {
                    for (int h = k + 1; h < n; h++)
                    {
                        dis[k, h] = double.MaxValue;
                    }
                }

                List <Pair>[] graph = Enumerable.Range(0, n).Select(s => new List <Pair>()).ToArray();;

                for (int k = 0; k < m; k++)
                {
                    ns = ReadIntArray();
                    var s      = ns[0] - 1;
                    var d      = ns[1] - 1;
                    var weight = Math.Log10(ns[2]);
                    graph[s].Add(new Pair(s, d, weight)
                    {
                        We = ns[2]
                    });
                    graph[d].Add(new Pair(d, s, weight)
                    {
                        We = ns[2]
                    });
                }

                List <Pair> path;

                MinimumSpanningTree.GetMinimumSpanningTree(graph, out path);

                long result = 1;

                foreach (var item in path)
                {
                    result = (result * item.We) % 1000000007;
                }

                Console.WriteLine(result);
            }

            Reader.Close();
        }
        public static int GetMinimumCost(int[,] graph, int k)
        {
            var costs = WarshallShortestPath.GetShortestCostsAndPath(graph).Item1;

            var newGraph = Enumerable.Range(0, k).Select(e => new List <Pair>()).ToArray();

            for (int a = 0; a < k; a++)
            {
                for (int b = a + 1; b < k; b++)
                {
                    newGraph[a].Add(new Pair(a, b, costs[a, b]));
                    newGraph[b].Add(new Pair(b, a, costs[a, b]));
                }
            }

            List <Pair> path;

            return(MinimumSpanningTree.GetMinimumSpanningTree(newGraph, out path));
        }