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

using namespace std;
set <int> m;

int main()
{
    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);
    int T, o, x;
    for (scanf("%d", &T); T--; ) {
        scanf("%d %d", &o, &x);
        switch (o) {
        case 1:
            m.insert(x);
            break;
        case 2:
            m.erase(x);
            break;
        case 3:
            printf("%d\n", m.find(x)!=m.end());
            break;
        }
    }
    return 0;
}