#include<cstdio>
#include<set>
using namespace std;
long int n,i,x,tip,m;
set<int>a;

void cauta()
{
    if(a.count(x))printf("1\n");
    else printf("0\n");
}

int main()
{
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);
    scanf("%ld",&n);
    for(i=1;i<=n;i++){
        scanf("%ld %ld",&tip,&x);
        if(tip==1)a.insert(x);
        else if(tip==2)a.erase(x);
        else cauta();
    }
    return 0;
}