#include <iostream>
#include <fstream>
#include <unordered_map>
using namespace std;

unordered_map<int, int> h;
int n, y;
long long x;
int main() {
    ifstream fin("hashuri.in");
    ofstream fout("hashuri.out");
    fin>>n;
    for (int i = 0; i < n; ++i) {
        fin>>y>>x;
        if (y == 1)
            h[x] = 1;
        else if (y == 2)
            h.erase(x);
        else
            fout<<h[x]<<endl;
    }
    return 0;
}