#include <bits/stdc++.h>
using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
int n,t,x;
unordered_set<int> h;
int main()
{
    f>>n;
    for(;n;n--)
    {
        f>>t>>x;
        if(t==1)h.insert(x);
        else if(t==2)h.erase(x);
        else h.find(x)==h.end()?g<<"0\n":g<<"1\n";
    }
    return 0;
}