#include <stdio.h>
#include <algorithm>
#include <cmath>
#include <cctype>
#include <cstring>
#include <vector>
#include <deque>
#include <set>
using namespace std;
#define Max 500001

set<int>s;

int main()
{
	int n,op,x;
	freopen("hashuri.in","r",stdin);
	freopen("hashuri.out","w",stdout);
		scanf("%d",&n);
		for(int i=1;i<=n;i++)
		{
			scanf("%d %d",&op,&x);
			switch(op)
			{
			case 1: s.insert(x); break;
			case 2: s.erase(x); break;
			case 3: printf("%d\n",s.find(x)!=s.end());
			}
		}
	return 0;
}