#include <stdio.h>
#include <set>

using namespace std;

set <int> s;

int main(){
    freopen("hashuri.in","r",stdin);
    freopen("hashuri.out","w",stdout);
    int n, op, x, nr = 0;
    scanf("%d", &n);
    while(n--){
        scanf("%d %d", &op, &x);
        if(op == 1)
            s.insert(x);
        if(op == 2)
            s.erase(x);
        if(op == 3)
            printf("%d\n",s.find(x) != s.end());
    }
    return 0;
}