#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, a;
    scanf("%d", &n);

    while(n--)
    {
        scanf("%d %d", &op, &a);
        switch(op)
        {
            case 1: s.insert(a); break;
            case 2: if(s.count(a)) s.erase(a); break;
            case 3: printf("%d\n", s.count(a)); break;
        }
    }
    fclose(stdin);
    fclose(stdout);
    return 0;
}