#include <iostream>
#include <fstream>
#include <set>

using namespace std;
ifstream in("hashuri.in");
ofstream out("hashuri.out");

#define ll long long
#define ull unsigned long long
#define pb push_back
const int NMax = 1e5 + 5;

int M;

int main() {
    in>>M;

    set<int> mySet;
    while (M--) {
        int tip,x;
        in>>tip>>x;

        switch(tip) {
        case 1: {
            mySet.insert(x);

            break;
        }
        case 2: {
            mySet.erase(x);

            break;
        }
        case 3: {
            out<<mySet.count(x)<<'\n';
        }
        }
    }

    in.close();out.close();
    return 0;
}