#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  set<int> st;
  int cnt[30]{};
  int q;
  cin >> q;
  while(q--) {
    int type;
    cin >> type;
    if (type == 1) {
      int x;
      cin >> x;
      auto [_, inserted] = st.insert(x);
      if (inserted) {
        rep(k, 30) cnt[k] += x >> k & 1;
      }
    } else if (type == 2) {
      int x;
      cin >> x;
      if (st.erase(x)) {
        rep(k, 30) cnt[k] -= x >> k & 1;
      }
    } else {
      int sz = st.size();
      int ans = -1;
      if (sz) {
        ans = 0;
        rep(k, 30) if (cnt[k] == sz) ans |= 1 << k;
      }
      cout << ans << '\n';
    }
  }
}