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