#include <fstream>
#include <cstdio>
#include <set>
using namespace std;
ifstream cin("hashuri.in");
int main()
{
	set<int> a;
	int x,op,n;
    freopen("hashuri.out", "w", stdout);
	cin>>n;
	for(int i=n-1; i>=0; i--)
	{
		cin>>op>>x;
		if(op==1)
		{
			a.insert(x);
			continue;
		}
		if(op==2)
		{
			a.erase(x);
			continue;
		}
		        printf("%d\n", a.find(x) != a.end());
	}
	return 0;
}