#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(),x.end() 
typedef long long ll;
//using mint = modint;
using mint = modint998244353;
using P = pair<int, int>;

const ll INF=1LL<<60, dx[]={0,1,0,-1},dy[]={1,0,-1,0};
template <typename T> inline bool chmin(T& a,const T&b) {if(a>b){a=b; return 1;} return 0;}
template <typename T> inline bool chmax(T& a,const T&b) {if(a<b){a=b; return 1;} return 0;}

int main(){

    int q;
    cin >> q;
    
    vector<int> cnt(30);
    map<ll,int> mp;
    int tot=0;

    rep(qi,q) {
        int type;
        cin >> type;
        if(type==1) {
            ll x;
            cin >> x;
            if(!mp[x]) {
                mp[x]++;
                rep(i,30) if((1ll<<i)&x) cnt[i]++;
                tot++;
            }
        } else if(type==2) {
            ll x;
            cin >> x;
            if(mp[x]) {
                mp[x]--;
                rep(i,30) if((1ll<<i)&x) cnt[i]--;
                tot--;
            }
        } else {
            if(tot==0) cout << -1 << endl;
            else {
                ll ans=0;
                rep(i,30) if(cnt[i]==tot) ans+=(1ll<<i);
                cout << ans << endl;
            }
        }
    }

    return 0;
}