#include <bits/stdc++.h>

#define cin fin
#define cout fout

using namespace std;
ifstream fin("hashuri.in");
ofstream fout("hashuri.out");

int n;
set<int> s;
int main()
{
    cin>>n;
    for(int i=1; i<=n; ++i)
    {
        int op, x;
        cin>>op>>x;
        if(op==1)
            s.insert(x);
        if(op==2)
            s.erase(x);
        if(op==3)
        {
            if(s.find(x)!=s.end())
                cout<<1<<'\n';
            else cout<<0<<'\n';
        }
    }
    return 0;
}