#include <cstdio>
#include <set>

using namespace std;

#define file_in "hashuri.in"
#define file_out "hashuri.out"

int Q,Tip,X;
set<int> S;


int main(){
	
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d", &Q);
	
	while(Q--){
		
		scanf("%d %d", &Tip, &X);
		
		if (Tip==1){
			S.insert(X);
		}
		else
		if (Tip==2){
			S.erase(X);
		}
		else{
			set<int> :: iterator it;
			int ok=0;
			for (it=S.begin();it!=S.end();++it)
				 if (*it==X){
					 ok=1;
					 continue;
				 }
			if (ok)
                printf("1\n");
			else
			    printf("0\n");
		}
    }

	return 0;
}