#include <cstdio>
#include <unordered_set>

using namespace std;

#define IN_FILE "hashuri.in"
#define OUT_FILE "hashuri.out"

int main( ) {
    FILE *f, *g;
    unordered_set < int > HASH;
    int Q, op, arg;

    f = fopen( IN_FILE, "r" );
    fscanf( f, "%d", &Q );
    g = fopen( OUT_FILE, "w" );
    while( Q-- ) {
        fscanf( f, "%d%d", &op, &arg );
        if( op == 1 ) // adaug
            HASH.insert( arg );
        else if( op == 2 )
            HASH.erase( arg );
        else if( HASH.find( arg ) == HASH.end( ) )
            fputs( "0\n", g );
        else
            fputs( "1\n", g );
    }
    fclose( f );
    fclose( g );
    return 0;
}