#include <stdio.h>
#include <algorithm>
#include <set>

using namespace std;

int main()
{
	int i, N, op, x;
	set<int> myset;

	freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);
	
	scanf("%d", &N);

	for(i = 1; i <= N; ++i)
	{
		scanf("%d%d", &op, &x);
		switch(op)
		{
		case 1:
			myset.insert(x);
			break;
		case 2:
			myset.erase(x);
			break;
		case 3:
			printf("%d\n", myset.find(x) != myset.end());
			break;
		}
	}

	return 0;
}