#include <cstdio>
#include <set>

using namespace std;

int main()
{int tip , nr , n ;
	set<int> s;
	freopen("hashuri.in","r",stdin);
	freopen("hashuri.out","w",stdout);
	scanf("%d",&n);
	for(int i=0;i<n;++i)
	{
		scanf("%d%d",&tip,&nr);
		if(tip==1)  s.insert(nr);
		else
		if(tip==2)  s.erase(nr);
		else
		if(tip==3) if(s.find(nr)!=s.end()) printf("1\n"); else printf("0\n");
	}
	return 0;
}