int main(void) {
ios::sync_with_stdio(false);
while (!cin.eof()) {
for (int i = 0; i < 5; i++) {
sets[i].clear();
}
universal_set.clear();
for (;;) {
string s; int n;
cin >> s >> n;
if (s != "R") {
for (int i = 0; i < n; i++) {
int k; cin >> k;
sets[s[0]-'A'].insert(k);
universal_set.insert(k);
}
} else {
string query;
cin >> query;
State begin = query.begin();
iset ans = expr(begin);
if (ans.empty()) {
cout << "NULL" << endl;
} else {
cout << *(ans.begin());
for (set<int>::const_iterator it = ++ans.begin(); it != ans.end(); it++) {
cout << ' ' << *it;
}
cout << endl;
}
break;
}
}
cin.ignore(); cin.peek();
}
static void lookup(const iset &data, spi sp)
{
citer res = std::lower_bound(data.begin(), data.end(), sp);
std::cout << *sp;
if (res == data.end() || *res != sp)
std::cout << " not found\n";
else
std::cout << " found\n";
}
static void lookup(const iset& data, spi sp)
{ // look for stored object that matches sp
citer res = lower_bound(data.begin(), data.end(), sp);
cout << *sp;
if (res == data.end() || *res != sp)
cout << " not found\n";
else
cout << " found\n";
}
iset term(State &begin) {
if (*begin == 'c') {
begin++;
iset ret;
iset s = factor(begin);
set_difference(
universal_set.begin(), universal_set.end(),
s.begin(), s.end(),
inserter(ret, ret.end()));
return ret;
} else {
return factor(begin);
}
}
