#include <iostream>
#include <unordered_map>

typedef long long ll;

using namespace std;
unordered_map<ll, int> M;
int N;

int main(){

    freopen("hashuri.in", "r", stdin);
   freopen("hashuri.out", "w", stdout);

    int op;
    ll x;

    scanf("%d", &N);

    for(int i=0; i<N;i++){
       scanf("%d %lld", &op, &x);
        if(op == 1)
            M[x] = 1;
        else
            if(op == 2)
                M.erase(x);
            else
                if(op == 3)
                    printf("%d\n", M.find(x)!=M.end());

    }
    return 0;
}