#include <bits/stdc++.h>

using namespace std;
ifstream f("hashuri.in");
ofstream g("hashuri.out");
unordered_set<int> s;
int n,t,x;
int main()
{
    f>>n;
    for(;n;n--){
    f>>t>>x;
    if(t==1){
        s.insert(x);
    }
    else if(t==2){
        s.erase(x);
    }
    else if(s.find(x)==s.end()){
        g<<"0\n";
    }

    else{
        g<<"1\n";
    }
}
}