#include <iostream>
#include <set>

using namespace std;
int main()
{
    unsigned int q, i, t;
    long x;
    set<long> s;
    cin >> q;
    for (i = 0; i < q; i++)
    {
        cin >> t;
        switch (t)
        {
        case 1:
            cin >> x;
            s.insert(x);
            break;
        case 2:
            cin >> x;
            s.erase(x);
            break;

        default:
            if (s.size() > 0)
            {
                x = (long(1) << 31) - 1;
                for (auto itr : s)
                    x = x & itr;
            }
            else
                x = -1;
            cout << x << endl;
            break;
        }
    }
}