#include <cstdio>
#include <set>

using namespace std;

int n;
set<int> A;

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

    int op,x,a;

    scanf("%i",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%i %i",&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;
}