#include<bits/stdc++.h>

using namespace std;

ifstream in("hasuri.in");
ofstream out("hasuri.out");

#define cin in
#define cout out

map<int,int> m ;

int main(){
    int n , tip , x ;
    cin >> n ;
    while(n--){
        cin >> tip >> x ;
        if(tip == 1 ){
            m[x]++;
            continue;
        }
        if(tip == 2)
        {
            m.erase(x);
            continue;

        }
        int z =  (m.find(x) != m.end());
        cout << z << '\n';
    }
}