#include <set>
#include <fstream>
using namespace std;
ifstream cin("hashuri.in");
ofstream cout("hashuri.out");
int n;
set<int>A;
int main(){
	int x,op;
	for(cin>>(n);n;--n){
		cin>>op>>x;
		if(op==1){
			A.insert(x);
			continue;
			}
			if(op==2){
				A.erase(x);
				continue;
				}
				cout<<'\n'<<(A.find(x)!=A.end());
		}
		return 0;
	}