#include <bits/stdc++.h>

 #define mem(a, val) memset((a), (val), sizeof a)

 #define all(a) (a).begin(), (a).end()

 #define pb push_back

 #define mp make_pair

 #define fir first

 #define sec second

 #define repu(i,a,b) for(int i=a;i<b;i++)

 using namespace std;

 typedef pair<int, int> pii;

 typedef long long LL;

 typedef unsigned long long LLU;

 const int maxn=;

 const int INF=0x3f3f3f3f;

 struct Edge

 {

     int u, v, d;

     Edge(int u, int v, int d):u(u), v(v), d(d) {}

 };

 struct qnode

 {

     int u, d;

     qnode(int u, int d):u(u), d(d) {}

     bool operator < (const qnode a)const

     {

         return d>a.d;

     }

 };

 struct Dijkstra

 {

     int n;

     vector<int> G[maxn];

     vector<Edge> edge;

     int d[maxn];

     bool vis[maxn];

     void init(int n)

     {

         this->n=n;

         for(int i=; i<=n; i++)

         {

             G[i].clear();

             vis[i]=;

             d[i]=INF;

         }

         edge.clear();

     }

     void AddEdge(int u, int v, int d)

     {

         G[u].push_back(edge.size());

         edge.push_back(Edge(u, v, d));

     }

     void dijkstra(int s)

     {

         priority_queue<qnode> q;

         d[s]=;

         q.push(qnode(s, ));

         while(!q.empty())

         {

             qnode x=q.top();

             q.pop();

             if(vis[x.u])continue ;

             vis[x.u]=true;

             for(int i=; i<G[x.u].size(); i++)

             {

                 Edge& e=edge[G[x.u][i]];

                 if(d[e.v]>d[x.u]+e.d)

                 {

                     d[e.v]=d[x.u]+e.d;

                     q.push(qnode(e.v, d[e.v]));

                 }

             }

         }

     }

 } dij1, dij2;

 int main()

 {

     int T, n, m, kase=;

     scanf("%d", &T);

     while(T--)

     {

         scanf("%d%d", &n, &m);

         dij1.init(n);///初始化不可缺

         dij2.init(n);

         repu(i,,m)

         {

             int u, v, w;

             scanf("%d%d%d", &u, &v, &w);

             dij1.AddEdge(u, v, w);///2条边，4个队列

             dij1.AddEdge(v, u, w);

             dij2.AddEdge(u, v, w);

             dij2.AddEdge(v, u, w);

         }

         int st,ed;

         scanf("%d%d",&st,&ed);

         dij1.dijkstra(st);///计算从st到每个顶点的最短距离

         dij2.dijkstra(ed);///计算从ed到每个顶点的最短距离

         int ans = ;

         repu(i,,n)

         {

             ans = max(ans,dij1.d[i]+dij2.d[i]);

             ///从st到i的距离+从ed到i的最短距离，即从st到ed的最短距离

             ///循环保证经过每一个点

         }

         printf("%d\n",ans);

     }

     return ;

 }