#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 998244353;
// constexpr int MOD = 1000000007;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  constexpr int B = 30;
  set<int> s;
  int zero[B]{};
  int q; cin >> q;
  while (q--) {
    int type; cin >> type;
    if (type == 3) {
      if (s.empty()) {
        cout << "-1\n";
      } else {
        int ans = 0;
        REP(b, B) {
          if (zero[b] == 0) ans |= 1 << b;
        }
        cout << ans << '\n';
      }
    } else {
      int x; cin >> x;
      if (type == 1) {
        if (s.emplace(x).second) {
          REP(b, B) {
            if (x >> b & 1) continue;
            ++zero[b];
          }
        }
      } else if (type == 2) {
        if (s.erase(x)) {
          REP(b, B) {
            if (x >> b & 1) continue;
            --zero[b];
          }
        }
      }
    }
  }
  return 0;
}