#include<stdio.h>
#include<set>
using namespace std;
set<int> s;
int main()
{
	freopen("hashuri.in","r",stdin);
	freopen("hashuri.out","w",stdout);
	int n,i,x,tip;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%d%d",&tip,&x);
		if(tip==1) s.insert(x);
		if(tip==2) s.erase(x);
		if(tip==3) printf("%d\n",s.count(x));
	}
	return 0;
}