#include <iostream>

#include <vector>

#include <string>

#include <cstdio>

#include <map>

#include <cstring>

using namespace std;

#define REP(i,n) for(int i=0;i<(n);++i)

#define FOR(i,a,b) for(int i=(a);i<=(b);++i)

void run() {

int N, mi = 1000000000, state = 0, total = 0;

cin >> N;

vector<int> mm(N);

REP(i,N) {

cin >> mm[i];

mi = min(mi, mm[i]);

total += mm[i];

state ^= mm[i];

}

if (state != 0) cout << "NO" << endl;

else cout << total - mi << endl;

}

int main() {

int kase;

cin >> kase;

FOR(k,1,kase) {

cout << "Case #" << k << ": ";

run();

}

return 0;

}