#include
    
         #include
     
          #include
      
           #include
       
            #define MAXN 1000010    #define LL long long    const LL INF = 0x7fffffffffffff;    using namespace std;    typedef struct{        int to,next;    }Node;    Node edge[2*MAXN];    int vis[MAXN/10],head[MAXN/10],val[MAXN/10];    LL sum[MAXN/10],all_sum,ans;    LL My_abs(LL tmp){return tmp < 0 ? -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] = 1;        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]= 1;        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 - 2*sum[u]));            }        }    }    int main(){        int n,m,cas = 0;        freopen("in.c","r",stdin);        while(~scanf("%d%d",&n,&m) && (m+n) ){            int k = 1,tmp,u,v;            all_sum = 0;            for(int i = 1;i <= n;i ++) scanf("%d",&tmp),val[i] = tmp,all_sum += tmp;            memset(head,-1,sizeof(head));            for(int i = 0;i < m;i ++){                scanf("%d%d",&u,&v);                addedge(u,v,k++);                addedge(v,u,k++);            }            memset(vis,0,sizeof(vis));            dfs_sum(1);            ans = INF;            memset(vis,0,sizeof(vis));            dfs_minabs(1);            if(n == 1) ans = val[1];            printf("Case %d: %lld\n",++cas,ans);        }        return 0;    }