#include <iostream>
#include <unordered_set>

int main() {

    FILE * fisier_out = fopen("hashuri.out", "w");
    FILE * fisier_in = fopen("hashuri.in", "r");
    int N, cod, x;
    std::unordered_set<int> mySet;

    fscanf(fisier_in, "%d", &N);
    for(int i = 0; i < N; i++){
        fscanf(fisier_in, "%d", &cod);
        fscanf(fisier_in, "%d", &x);

        if(cod == 1){
            mySet.insert(x);
        }

        if(cod == 2){
            mySet.erase(x);
        }

        if(cod == 3){
            fprintf(fisier_out, "%d\n", (int)mySet.count(x));
        }
    }
    return 0;
}