#include<stdio.h>
#include<map>

using namespace std;

FILE*f=fopen("hashuri.in","r");
FILE*g=fopen("hashuri.out","w");

int i,m,op,x,nr; map<int,int> M;

int main () {
	
	fscanf(f,"%d",&m);
	
	for ( i = 1 ; i <= m ; ++i ){
		
		fscanf(f,"%d %d",&op,&x);
		
		if ( op == 1 ){
			if ( M.find(x) == M.end() )
				M[x] = i;
		}
		else if ( op == 2 ){
			M.erase(x);
		}
		else{
			fprintf(g,"%d\n",M.find(x) != M.end() );
		}
		
	}
	
	fclose(f);
	fclose(g);
	
	return 0;
}