#include <fstream>
#include <set>
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
set<int>A;
int main()
{
    int N;
    f>>N;
    for(int i=1;i<=N;i++)
    {   int x,y;
        f>>x>>y;
        if(x==1) A.insert(y);
        if(x==2) A.erase(y);
        if(x==3) g<<(A.find(y)!=A.end())<<'\n';
    }
    return 0;
}