#include<iostream>

     #include<cstdio>

     #include<cstring>

     #include<string>

     #define MAXN 1000010

     #define LL long long

     const LL INF = 0x7fffffffffffff;

     using namespace std;

     typedef struct{

         int to,next;

     }Node;

     Node edge[*MAXN];

     int vis[MAXN/],head[MAXN/],val[MAXN/];

     LL sum[MAXN/],all_sum,ans;

     LL My_abs(LL tmp){return tmp <  ? -tmp : tmp;}

     void addedge(int u,int v,int k){

         edge[k].to = v;

         edge[k].next = head[u];

         head[u] = k;

     }

     LL dfs_sum(int s){

         vis[s] = ;

         sum[s] = val[s];

         for(int i = head[s];~i;i = edge[i].next){

             int u = edge[i].to;

             if(!vis[u]) sum[s] += dfs_sum(u);

         }

         return sum[s];

     }

     void dfs_minabs(int s){

         vis[s]= ;

         for(int i  = head[s];~i;i = edge[i].next){

             int u = edge[i].to;

             if(!vis[u]){

                 dfs_minabs(u);

                 ans = min(ans,My_abs(all_sum - *sum[u]));

             }

         }

     }

     int main(){

         int n,m,cas = ;

         freopen("in.c","r",stdin);

         while(~scanf("%d%d",&n,&m) && (m+n) ){

             int k = ,tmp,u,v;

             all_sum = ;

             for(int i = ;i <= n;i ++) scanf("%d",&tmp),val[i] = tmp,all_sum += tmp;

             memset(head,-,sizeof(head));

             for(int i = ;i < m;i ++){

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

                 addedge(u,v,k++);

                 addedge(v,u,k++);

             }

             memset(vis,,sizeof(vis));

             dfs_sum();

             ans = INF;

             memset(vis,,sizeof(vis));

             dfs_minabs();

             if(n == ) ans = val[];

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

         }

         return ;

     }