#include <iostream>
#define ULL unsigned long long

using namespace std;

int n;
ULL a[100];

ULL work(int ni,ULL now)
{
ULL ans=1e19;
if(ni==n)
{
return now;
}
else
{
ans=min(ans,work(ni+1,now&a[ni]));
if(ans==0)
{
return 0;
}
ans=min(ans,work(ni+1,now|a[ni]));
if(ans==0)
{
return 0;
}
ans=min(ans,work(ni+1,now^a[ni]));
if(ans==0)
{
return 0;
}
ans=min(ans,work(ni+1,now&~a[ni]));
if(ans==0)
{
return 0;
}
ans=min(ans,work(ni+1,now|~a[ni]));
if(ans==0)
{
return 0;
}
ans=min(ans,work(ni+1,now^~a[ni]));
if(ans==0)
{
return 0;
}
}
return ans;
}

int main()
{
int t,i,j;
cin>>t;
for(i=1;i<=t;i++)
{
cout<<"Case #"<<i<<": ";
cin>>n;
for(j=0;j<n;j++)
{
cin>>a[j];
}
if(n==1)
{
cout<<a[0]<<endl;
}
else
{
cout<<min(work(1,a[0]),work(1,~a[0]))<<endl;
}
}
return 0;
}