#include <cstdio>
#include <unordered_set>

using namespace std;

unordered_set <int> s;

int main() {
  int n, nr, ver;
  FILE *fin, *fout;
  fin = fopen( "hashuri.in", "r" );
  fout = fopen( "hashuri.out", "w" );
  fscanf( fin, "%d", &n );
  for ( int i = 0; i < n; i++ ) {
    fscanf( fin, "%d%d", &ver, &nr );
    if ( ver == 1 )
      s.insert( nr );
    else if ( ver == 2 )
      s.erase( nr );
    else
      fprintf( fout, "%d\n", s.find( nr ) != s.end() );
  }
  fclose( fin );
  fclose( fout );
  return 0;
}