#include <iostream>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <fstream>
std::ifstream in("hashuri.in");
std::ofstream out("hashuri.out");


int main() {
    int n, op, x;
    std::set<int> hash;
    in>>n;
    for(int i = 1; i<=n; i++)
    {
        in>>op>>x;
        if(op == 1)
            hash.insert(x);
        else if(op == 2)
            hash.erase(x);
        else if(op == 3)
            std::cout<<(hash.find(x) != hash.end());
    }
    return 0;
}