#include <cstdio>
#include <map>
using namespace std;
int n,c,nr;
map<int,int> a;
int main()
{
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);
    scanf("%d ",&n);
    for(int i=0;i<n;++i){
        scanf("%d %d ",&c,&nr);
        if(c==1&&a.find(nr)==a.end())
                a[nr]=1;
        if(c==2)
            a.erase(nr);
        if(c==3)
           printf("%d\n",a.find(nr) != a.end());
    }
    return 0;
}