1 #include<cstdio>
 2 #include<cstring>
 3 #include<queue>
 4 #include<vector>
 5 #include<algorithm>
 6 using namespace std;
 7 
 8 struct edge
 9 {
10     int u,v,w;
11     edge(int u,int v,int w):u(u),v(v),w(w){};
12 };
13 
14 struct heapnode
15 {
16     int u,d;
17     bool operator < (const heapnode& temp)const
18     {
19         return d>temp.d;
20     }
21 };
22 
23 vector<int>G[1005];
24 vector<edge>edges;
25 const int inf=0x3f3f3f3f;
26 int vis[1005];
27 int d[1005];
28 int ed;
29 int m,n;
30 
31 void init()
32 {
33     for(int i=1;i<=m;i++)
34         G[i].clear();
35     edges.clear();
36 }
37 
38 void addedge(int u,int v,int w)
39 {
40     edges.push_back(edge(u,v,w));
41     int m=edges.size();
42     G[u].push_back(m-1);
43 }
44 
45 void dijkstra(int ed)
46 {
47     memset(vis,0,sizeof(vis));
48     priority_queue<heapnode>q;
49     q.push((heapnode){ed,0});
50     for(int i=1;i<=m;i++)
51         d[i]=inf;
52     d[ed]=0;
53     while(!q.empty())
54     {
55         int u=q.top().u;
56         q.pop();
57         if(vis[u])
58             continue;
59         vis[u]=1;
60         for(int i=0;i<G[u].size();i++)
61         {
62             edge& e=edges[G[u][i]];
63             if(d[e.v]>d[u]+e.w)
64             {
65                  d[e.v]=d[u]+e.w;
66                  q.push((heapnode){e.v,d[e.v]});
67             }
68         }
69     }
70 }
71 
72 int main()
73 {
74     int st,a,b,c,num;
75     while(scanf("%d%d%d",&m,&n,&ed)!=EOF)
76     {
77         init();
78         for(int i=0;i<n;i++)
79         {
80             scanf("%d%d%d",&a,&b,&c);
81             addedge(b,a,c);
82         }
83         dijkstra(ed);
84         scanf("%d",&num);
85         int ans=inf;
86         while(num--)
87         {
88             scanf("%d",&st);
89             ans=min(ans,d[st]);
90         }
91         if(ans==inf)
92             printf("-1\n");
93         else
94             printf("%d\n",ans);
95     }
96     return 0;
97 }