#include <bits/stdc++.h>

using namespace std;
unordered_set<string> s;
ifstream in("hashuri.in");
ofstream out("hashuri.out");
int main(){
    int n;
    in>>n;
    for(;n;n--){
        char c;
        string x;
        in>>c>>x;
        if (c=='1'){s.insert(x);continue;}
        if (c=='2'){s.erase(x);continue;}
        if (c=='3'){out<<(s.find(x)!=s.end())<<'\n';continue;}
    }
}