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

using namespace std;

int N, NR;
set <int> M;

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

    int i, tip, x;

    scanf("%d ", &N);

    for (i = 1; i <= N; i++)
    {
        scanf("%d %d ", &tip, &x);

        if (tip == 1 && M.find(x)==M.end()) M.insert( x );
        if (tip == 2) M.erase(x);
        if (tip == 3) printf("%d\n", M.find(x) != M.end());
    }

    return 0;
}