> #include<stdio.h>
> #include<string.h>
> #include<vector>
> 
> using namespace std;
> 
> vector<long> con[100001];
> _int64 val[100001];
> _int64 sum,min;
> long n;
> int u[100001];
> 
> _int64 search(long x)
> {
> 	_int64 s;
> 	_int64 z,mm;
> 	u[x]=1;
> 	s=val[x];
> 	mm=min;
> 	for (vector<long> ::iterator i = con[x].begin(); i != con[x].end(); i++)
> 		if (!u[*i])
> 		{
> 			z=search(*i);
> 			if (mm>abs(sum-z-z)) mm=abs(sum-z-z);
> 			s=s+z;
> 		}
> 	if (mm>abs(s+s-sum)) mm=abs(s+s-sum);
> 	if (mm<min) min=mm;
> 	return s;
> }
> 
> int main()
> {
> 	long i,p,m;
> 	long b,c;
> 	p=1;
> 	scanf("%ld%ld",&n,&m);
> 	while (!(n==0&&m==0))
> 	{
> 		for (i=1;i<=n;i++)
> 			con[i].clear();
> 		sum=0;
> 		for (i=1;i<=n;i++)
> 		{
> 			scanf("%I64d",&val[i]);
> 			sum=sum+val[i];
> 		}
> 		for (i=1;i<=m;i++)
> 		{
> 			scanf("%ld%ld",&b,&c);
> 			con[b].push_back(c);
> 			con[c].push_back(b);
> 		}
> 		min=abs(sum-val[1]-val[1]);
> 		memset(u,0,sizeof(u));
> 		search(1);
> 		printf("Case %ld: %I64d\n",p,min);
> 		p++;
> 		scanf("%ld%ld",&n,&m);
> 	}
> 	return 0;
> }