include
include
include
using namespace std;
int main() {
list<int>a;
int x, sum = 0;
cin >> x;
int s;
cin >> s;
for (; x != -1;) {
if (a.size() > 0) {
a.pop_back();
}else {
cout << "not found";
}
if (sum = s) {
cout << ;
}
}
return 0;
}