#include<cstdio>
#include<set>
#include<fstream>
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int n;
set<int> a;
int main()
{
    int op, x;
    f>>n;
	for(;n;--n)
    {
        f>>op>>x;
        if (op == 1)
        {
            a.insert(x);
            continue;
        }
        if (op == 2)
        {
            a.erase(x);
            continue;
        }
		if(a.find(x)!=a.end())
			g<<1<<"\n";
		else
			g<<0<<"\n";
    }
    
    return 0;
}