#include <fstream>
#include <unordered_set>
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int n, c, a;
unordered_set <int> mySet;
int main()
{
	f >> n;

	for (int i = 0; i < n; ++i)
	{
		f >> c >> a;
		if (c == 1)
			mySet.insert(a);
		else 
			if (c == 2)
			    mySet.erase(a);
		else
			g << (mySet.find(a) != mySet.end()) << '\n';
	}
}