#include<stdio.h>
#include<set>
using namespace std;

#define FIN "hashuri.in"
#define FOUT "hashuri.out"

set<int> s;
int n;

int main()
{
    freopen(FIN,"r",stdin);
    freopen(FOUT,"w",stdout);
    int x,y;
    set<int>::iterator it;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%d %d", &x,&y);

        switch(x)
        {
        case 1:
            s.insert(y);
            break;
        case 2:
            s.erase(y);
            break;
        case 3:
            it=s.find(y);
            if(it!=s.end())
            {
                printf("%d\n",1);
            }
            else printf("%d\n",0);
        }
    }

    return 0;
}