#include <cstdio>
#include <unordered_set>

int main()
{
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);

    std::unordered_set<int> hash; //nu merita ceva mai complicat :)
    int n,i,op,x;

    scanf("%d",&n);
    for(i=0;i<n;i++) {
        scanf("%d %d",&op,&x);
        if(op==1) hash.insert(x);
        if(op==2) hash.erase(x);
        if(op==3) printf("%d\n",hash.count(x));
    }

    return 0;
}