#include <iostream>
#include <fstream>
#include <map>

using namespace std;

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