#include <cstdio>
#include <map>

using namespace std;

map<int,int> m;

inline void adauga( int x )
{
  m[x]=1;
}

inline void elimina( int x )
{
  m.erase(x);
}

inline int verifica( int x )
{
  return (m.find(x)!=m.end());
}

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

  int n, op, k;

  scanf( "%d", &n );

  for( int i=1;i<=n;i++ )
  {
    scanf( "%d%d", &op, &k );

    if( op==1 )
      adauga(k);
    else
      if( op==2 )
        elimina(k);
      else
        printf( "%d\n", verifica(k) );
  }

  return 0;
}