#include<cstdio>
#include<set>
using namespace std;
 
int main()
{
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);
   
    int i,n,operatie,x;
    set<int> multime;
   
    scanf("%d",&n);
    for(i=1; i<=n; i++)
    {
        scanf("%d %d",&operatie,&x);
        if(operatie==1)
        {
            multime.insert(x);
            continue;
        }
        if(operatie==2)
        {
            multime.erase(x);
            continue;
        }
        printf("%d\n",multime.find(x)!=multime.end());
    }
    return 0;
}