#include <fstream>
#include <unordered_set>
using namespace std;

typedef unordered_set<int> hashy;

hashy V;

int main(int argc, const char * argv[]) {
    
    ifstream fi ("hashuri.in");
    ofstream fo ("hashuri.out");
    int P,op,n;
    
    for (fi >> P; P ; -- P)
    {
        fi >> op >> n;
        switch (op)
        {
            case 1: V.insert(n); break;
            default:
            {
                hashy::const_iterator pointer = V.find(n);
                
                if (pointer == V.end())
                {
                    if (op == 3)
                        fo << 0 << '\n';
                }
                
                else
                {
                    if (op == 2)
                        V.erase(n);
                    else fo << 1 << '\n';
                    
                }
                
                break;
            }
        }
        
    }
    return 0;
}