#include <stdio.h>
#include <stdlib.h>
#include <map>
#include <set>
#include <fstream>

int main () {
    int numberOfTests;
    int operationKind;
    long long int element;
    std::set<long long int> elements;
    std::ifstream in("hashuri.in");
    std::ofstream out("hashuri.out");

    in >> numberOfTests;

    for (int i = 0; i < numberOfTests; i++) {
        in >> operationKind >> element;
        switch (operationKind) {
            case 1:
                elements.insert(element);
                break;
            case 2:
                elements.erase(element);
                break;
            case 3:
                out << (elements.find(element) != elements.end()) << "\n";
                break;
            default:
                break;
        }
    }

    return 0;
}