#include <cstdio>
#include <unordered_map>

using namespace std;

unordered_map<int,char> h;

int main()
{
    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);
    int n,tip,x;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%d%d",&tip,&x);
        if(tip==1) h[x]=1;
        else if(tip==2) h.erase(x);
        else printf("%d\n",h.count(x));
    }
    return 0;
}