#include <bits/stdc++.h>
using namespace std;
unordered_set<int> S;
int main(){
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);
    int n;
    scanf("%d",&n);
    while(n--){
        int tip,x;
        scanf("%d %d",&tip,&x);
        if(tip==1) S.insert(x);
        else if(tip==2) S.erase(x);
        else printf("%d\n",S.find(x)!=S.end());
    }
    return 0;
}