RT orz
```c++
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <ctime>

using std::cin;
using std::cout;
using std::endl;
using std::sort;

unsigned int data[128];
int n;
int min;

unsigned int calc(int i,int a,int b){
if(i==0)
return (a|b);
if(i==1)
return (a&b);
if(i==2)
return (a^b);
return a|b;
}

void search(int i,unsigned int r){
if(i+1==n){
min = (r<min)?r:min;
return;
}
unsigned int crr;
int x = i+1;
crr = data[x];
for(int y=0;y<3;y++){
search(x,calc(y,crr,r));
}
crr = ~crr;
for(int y=0;y<3;y++){
search(x,calc(y,crr,r));
}
}

int main(int argc,char ** argv){
int t;
cin>>t;
int ta = t;
while(t--){
cin>>n;
for(int x=0;x!=n;x++){
cin>>data[x];
}
if(n>8){
cout<<"Case #"<<(ta-t)<<": "<<0<<endl;
}else if(n==1){
cout<<"Case #"<<(ta-t)<<": "<<data[0]<<endl;
}else{
min = (0xFFFFFFFF>>1);
search(0,data[0]);
search(0,~data[0]);
cout<<"Case #"<<(ta-t)<<": "<<min<<endl;
}
}
return 0;
}
```