#include <iostream>
#include <fstream>
#include <set>
using namespace std;

int main(){
    set<long> a;
    long n,i,op,x;
    ifstream f("hashuri.in");
    ofstream g("hashuri.out");
    f>>n;
    for(i=0;i<n;i++){
        f>>op>>x;
        if(op==1)
            a.insert(x);
        else if(op==2)
            a.erase(x);
        else if(op==3)
            g<<(a.find(x)!=a.end())<<'\n';

    }
    return 0;
}


/*
---30 puncte---
#include <iostream>
#include <fstream>
using namespace std;

long long n,i,op,x,ap[200000000];
int main()
{
    ifstream f("hashuri.in");
    ofstream g("hashuri.out");
    f>>n;
    for(i=0;i<n;i++){
        f>>op>>x;
        if(op==1)
            ap[x]='1';
        else if(op==2)
            ap[x]='0';
        else if(op==3)
            if(ap[x]=='1')
                g<<'1'<<'\n';
            else g<<'0'<<'\n';
    }
    return 0;
}
---30 puncte---
*/