#include<fstream>
#include<set>
using namespace std;
int T, op, x;
set<int> s;
ifstream in("hashuri.in");
ofstream out("hashuri.out");
int main(){
    in>>T;
    for(;T--;){
        in>>op>>x;
        if(op==1){
            s.insert(x);
            continue;
        }
        if(op==2){
            s.erase(x);
            continue;
        }
        s.find(x)!=s.end()?out<<"1\n":out<<"0\n";
    }
return 0;
}