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

using namespace std;

int n;
set <int> sol;

int main()
{
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);
    scanf("%d",&n);
    int x,y;
    for(int i=1;i<=n;i++)
     {
      scanf("%d %d",&x,&y);
      if(x==1)
       {
        sol.insert(y);
        continue;
       }
      if(x==2)
       {
        sol.erase(y);
        continue;
       }
       printf("%d\n", sol.find(y) != sol.end());
     }
    return 0;
}