#include <iostream>
#include <fstream>

using namespace std;

const unsigned FNV_offset_basis = 2166136261;
const unsigned FNV_prime = 16777619;

const unsigned NR = 20;
const unsigned MASK = ( 1 << 20 );

const int STERS = -1;

unsigned FNV( unsigned x )
{
    unsigned hsh = FNV_offset_basis;
    hsh = hsh ^ x;
    hsh = hsh * FNV_prime;
    return ( hsh & ( MASK - 1 ) );
}

unsigned HT[MASK];

int valid( int pos, int value )
{
    return HT[pos] && HT[pos] != value;
}

unsigned position( int value )
{
    int pos = FNV( value );

    while ( valid( (value + pos) & ( MASK - 1 ), value ) ) pos++;

    return (value + pos) & ( MASK - 1 );
}

void insert( int value )
{
    HT[ position( value ) ] = value;
}

bool find( int value )
{
    return HT[ position( value ) ] == value;
}

void erase( int value )
{
    int pos = position( value );

    if ( HT[pos] == value ) HT[pos] = -1;
}

int N;
unsigned key, type;

const int DIM_BUFF = ( 1 << 20 );

char buffer[DIM_BUFF];
int position1 = DIM_BUFF;

char GetChar()
{
    if ( position1 == DIM_BUFF )
    {
        fread( buffer, 1, DIM_BUFF, stdin );
        position1 = 0;
    }

    return buffer[ position1++ ];
}

unsigned rd()
{
    unsigned nr = 0;
    char c;

    scanf("%d", &nr);

    /*

    do
    {
        c = GetChar();

    } while ( !isdigit( c ) );

    do
    {
        nr = nr * 10 + ( c - '0' );
        c = GetChar();

    } while ( isdigit( c ) );*/

    return nr;
}

int main()
{
    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);

    N = rd();

    while ( N-- )
    {
        type = rd(); key = rd();

        if ( type == 1 ) insert( key );
        if ( type == 2 ) erase( key );
        if ( type == 3 ) printf("%d\n", find( key ) );
    }

    return 0;
}