#include<fstream>
#include<cstdio>
#include<set>
using namespace std;
set<int>multime;
int main(){
	int k,x,n;
	ifstream f;
	f.open("hashuri.in");
	freopen("hashuri.out","w",stdout);
	f>>n; 
	for(int i=1;i<=n;++i){
		f>>k>>x; 
		switch(k){
		case 1: multime.insert(x); break;
		case 2: multime.erase(x); break;
		case 3: if(multime.find(x)!=multime.end()) printf("1\n"); else printf("0\n"); break;
		}
	}
	f.close();
	return 0;
}