#include <fstream>
#include <unordered_set>
using namespace std;

int main()
{
	ifstream in("hashuri.in");
	ofstream out("hashuri.out");
	
	int n;
	in >> n;
	
	unordered_set<int> st;
	for(int i = 0;i < n;++i)
	{
		int op, val;
		in >> op >> val;
		
		if(op == 1)
		{
			st.insert(val);
		}
		else if(op == 2)
		{
			st.erase(val);
		}
		else
		{
			if(st.find(val) != st.end())
			{
				out<<"1\n";
			}
			else
			{
				out<<"0\n";
			}
		}
	}
	in.close();
	out.close();
}