1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<queue>
 6 #include<vector>
 7 using namespace std;
 8 #define inf 1<<30
 9
10 struct Edge{
11     int v,w;
12     Edge(){}
13     Edge(int vv,int ww):v(vv),w(ww){}
14 };
15
16 vector<vector<Edge> >g;
17 int cost[111],dist[111],dp[111][111];
18 bool mark[111];
19 int n,m,Q;
20
21 void spfa(int s)
22 {
23     memset(mark,false,sizeof(mark));
24     fill(dist,dist+n+1,inf);
25     dist[s]=0;
26     queue<int>que;
27     que.push(s);
28     while(!que.empty()){
29         int u=que.front();
30         que.pop();
31         mark[u]=false;
32         for(int i=0;i<g[u].size();i++){
33             int v=g[u][i].v,w=g[u][i].w;
34             if(dist[u]+w<dist[v]&&cost[v]<=cost[s]){
35                 dist[v]=dist[u]+w;
36                 if(!mark[v]){
37                     mark[v]=true;
38                     que.push(v);
39                 }
40             }
41         }
42     }
43     for(int i=1;i<=n;i++)dp[s][i]=dist[i];
44 }
45
46
47 int main()
48 {
49     int u,v,w,t=0;
50     while(~scanf("%d%d%d",&n,&m,&Q)){
51         if(n==0&&m==0&&Q==0)break;
52         for(int i=1;i<=n;i++)scanf("%d",&cost[i]);
53         g.clear();
54         g.resize(n+2);
55         while(m--){
56             scanf("%d%d%d",&u,&v,&w);
57             g[u].push_back(Edge(v,w));
58             g[v].push_back(Edge(u,w));
59         }
60         for(int i=1;i<=n;i++)
61             for(int j=1;j<=n;j++)dp[i][j]=inf;
62         for(int i=1;i<=n;i++)spfa(i);
63         if(t)puts("");
64         printf("Case #%d\n",++t);
65         while(Q--){
66             scanf("%d%d",&u,&v);
67             int ans=inf;
68             for(int i=1;i<=n;i++){
69                 if(dp[i][u]==inf||dp[i][v]==inf)continue;
70                 ans=min(ans,dp[i][u]+dp[i][v]+cost[i]);
71             }
72             if(ans==inf)ans=-1;
73             printf("%d\n",ans);
74         }
75     }
76     return 0;
77 }
78
79