#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<queue>

 using namespace std;

 #define MAXN 22222

 #define MAXM 222222

 #define inf 1<<30

 #define FILL(a,b) memset(a,b,sizeof(a))

 template<class T>inline T Get_Min(const T &a,const T &b){ return a<b?a:b; }

 template<class T>inline T Get_Max(const T &a,const T &b){ return a>b?a:b; }

 struct Edge{

     int v,w,next;

 }edge1[MAXM],edge2[MAXM];

 int n,m,st,ed,p,NE1,NE2;

 int head1[MAXN],head2[MAXN];

 void Insert1(int u,int v,int w)

 {

     edge1[NE1].v=v;

     edge1[NE1].w=w;

     edge1[NE1].next=head1[u];

     head1[u]=NE1++;

 }

 void Insert2(int u,int v,int w)

 {

     edge2[NE2].v=v;

     edge2[NE2].w=w;

     edge2[NE2].next=head2[u];

     head2[u]=NE2++;

 }

 int dist[][MAXN];

 bool mark[MAXN];

 void spfa(int st,int ed,Edge *edge,int *dist,int *head)

 {

     FILL(mark,false);

     fill(dist,dist+n+,inf);

     queue<int>que;

     que.push(st);

     dist[st]=;

     while(!que.empty()){

         int u=que.front();

         que.pop();

         mark[u]=false;

         for(int i=head[u];i!=-;i=edge[i].next){

             int v=edge[i].v,w=edge[i].w;

             if(dist[u]+w<dist[v]){

                 dist[v]=dist[u]+w;

                 if(!mark[v]){

                     mark[v]=true;

                     que.push(v);

                 }

             }

         }

     }

 }

 int main()

 {

     int _case,u,v,w,ans,t=;

     scanf("%d",&_case);

     while(_case--){

         scanf("%d%d%d%d%d",&n,&m,&st,&ed,&p);

         NE1=NE2=;

         FILL(head1,-);

         FILL(head2,-);

         while(m--){

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

             Insert1(u,v,w);

             Insert2(v,u,w);

         }

         spfa(st,ed,edge1,dist[],head1);

         spfa(ed,st,edge2,dist[],head2);

         ans=-;

         for(int u=;u<=n;u++){

             for(int i=head1[u];i!=-;i=edge1[i].next){

                 int v=edge1[i].v,w=edge1[i].w;

                 if(dist[][u]!=inf&&dist[][v]!=inf&&dist[][u]+w+dist[][v]<=p){

                     ans=Get_Max(ans,w);

                 }

             }

         }

         printf("Case %d: %d\n",t++,ans);

     }

     return ;

 }