// 入力フォーマットチェック
#pragma GCC optimize ( "O3" )
#pragma GCC target ( "avx" )
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define TYPE_OF( VAR ) remove_const<remove_reference<decltype( VAR )>::type >::type
#define UNTIE ios_base::sync_with_stdio( false ); cin.tie( nullptr ) 
#define CEXPR( LL , BOUND , VALUE ) constexpr const LL BOUND = VALUE 
#define CIN( LL , A ) LL A; cin >> A 
#define ASSERT( A , MIN , MAX ) assert( MIN <= A && A <= MAX ) 
#define CIN_ASSERT( A , MIN , MAX ) CIN( TYPE_OF( MAX ) , A ); ASSERT( A , MIN , MAX ) 
#define GETLINE( A ) string A; getline( cin , A ) 
#define GETLINE_SEPARATE( A , SEPARATOR ) string A; getline( cin , A , SEPARATOR ) 
#define FOR( VAR , INITIAL , FINAL_PLUS_ONE ) for( TYPE_OF( FINAL_PLUS_ONE ) VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) 
#define FOREQINV( VAR , INITIAL , FINAL ) for( TYPE_OF( INITIAL ) VAR = INITIAL ; VAR >= FINAL ; VAR -- ) 
#define REPEAT( HOW_MANY_TIMES ) FOR( VARIABLE_FOR_REPEAT , 0 , HOW_MANY_TIMES ) 
#define QUIT return 0 
#define RETURN( ANSWER ) cout << ( ANSWER ) << "\n"; QUIT 

// 入力フォーマットチェック用
// 余分な改行を許さない
#define CHECK_REDUNDANT_INPUT string VARIABLE_FOR_CHECK_REDUNDANT_INPUT = ""; cin >> VARIABLE_FOR_CHECK_REDUNDANT_INPUT; assert( VARIABLE_FOR_CHECK_REDUNDANT_INPUT == "" ); assert( ! cin );
// #define CHECK_REDUNDANT_INPUT string VARIABLE_FOR_CHECK_REDUNDANT_INPUT = ""; getline( cin , VARIABLE_FOR_CHECK_REDUNDANT_INPUT ); assert( VARIABLE_FOR_CHECK_REDUNDANT_INPUT == "" ); assert( ! cin );
// |N| <= BOUNDを満たすNをSから構築
#define STOI( S , N , BOUND ) TYPE_OF( BOUND ) N = 0; { bool VARIABLE_FOR_POSITIVITY_FOR_STOI = true;  assert( S != "" ); if( S.substr( 0 , 1 ) == "-" ){ VARIABLE_FOR_POSITIVITY_FOR_STOI = false; S = S.substr( 1 ); assert( S != "" ); } assert( S.substr( 0 , 1 ) != " " ); while( S == "" ? false : S.substr( 0 , 1 ) != " " ){ assert( N < BOUND / 10 ? true : N == BOUND / 10 && stoi( S.substr( 0 , 1 ) ) <= BOUND % 10 ); N = N * 10 + stoi( S.substr( 0 , 1 ) ); S = S.substr( 1 ); } if( ! VARIABLE_FOR_POSITIVITY_FOR_STOI ){ N *= -1; } if( S != "" ){ S = S.substr( 1 ); } } 
// 1行で入力される変数の個数が適切か確認（半角空白の個数+1を調べる）
#define COUNT_VARIABLE( S , VARIABLE_NUMBER ) { int size = S.size(); int count = 0; for( int i = 0 ; i < size ; i++ ){ if( S.substr( i , 1 ) == " " ){ count++; } } assert( count + 1 == VARIABLE_NUMBER ); } 

int main()
{
  UNTIE;
  CEXPR( int , bound_Q , 400000 );
  CIN_ASSERT( Q , 1 , bound_Q );
  CEXPR( int , length , 30 );
  CEXPR( ll , bound_x , ( ll(1) << length ) - 1 );
  map<ll,bool> S{};
  int A[length] = {};
  ll answer;
  REPEAT( Q ){
    CIN_ASSERT( num , 1 , 3 );
    if( num == 1 ){
      CIN_ASSERT( x , 0 , bound_x );
      if( S.count( x ) == 0 ){
	S[x] = true;
	FOR( i , 0 , length ){
	  if( x % 2 == 0 ){
	    A[i]++;
	  }
	  x /= 2;
	}
      }
    } else if( num == 2 ){
      CIN_ASSERT( x , 0 , bound_x );
      if( S.count( x ) == 1 ){
	S.erase( x );
	FOR( i , 0 , length ){
	  if( x % 2 == 0 ){
	    A[i]--;
	  }
	  x /= 2;
	}
      }
    } else {
      answer = 0;
      FOREQINV( i , length - 1 , 0 ){
	answer *= 2;
	if( A[i] == 0 ){
	  answer++;
	}
      }
      cout << ( answer == bound_x ? -1 : answer ) << "\n";
    }
  }
  CHECK_REDUNDANT_INPUT;
  QUIT;
}