#include <stdio.h>
#include <set>

using namespace std;

int N;
set<int> A;

int main()
{
    int op, x;

    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);
    for (scanf("%d", &N); N; --N)
    {
        scanf("%d %d", &op, &x);
        if (op == 1)
        {
            A.insert(x);
            continue;
        }
        if (op == 2)
        {
            A.erase(x);
            continue;
        }
        printf("%d\n", A.find(x) != A.end());
    }
    return 0;
}