#include <stdio.h>
#include <unordered_set>

using namespace std;

#define ll long long unsigned
#define pb push_back
#define mp make_pair

unordered_set <int> s;

int main(){
    int n,i,op,x;
    freopen("maxk.in", "r", stdin);
    freopen("maxk.out", "w", stdout);
    scanf("%d",&n);
    for(i = 1;i <= n;i++){
        scanf("%d %d",&op,&x);
        if(op == 1){
            s.insert(x);
        }else if(op == 2){
            s.erase(x);
        }else{
            if(s.find(x) != s.end()){
                printf("1\n");
            }else{
                printf("0\n");
            }
        }
    }
    return 0;
}