#include<bits/stdc++.h>
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int n, p, x, nr, minim, k;
set<int>v;
int main()
{
    f>>n;
    for(int i=1; i<=n; i++)
    {
        f>>p;
        if(p==1)
        {
            f>>x;
            if(!v.count(x)) v.insert(x);
            else continue;
        }
        else if(p==2)
        {
            f>>x;
            if(v.count(x)) v.erase(x);
            else continue;
        }
        else
        {
            f>>x;
            g<<(v.count(x))<<'\n';
        }
    }
    return 0;
}