#include <cstdio>
#include <unordered_set>

using namespace std;

#define gc getchar
#define isdigit(c) (c>='0'&&c<='9')
char c;
void Read(int &a) {
    for(c=gc(); !isdigit(c); c=gc());
    for(a=0; isdigit(c); a=a*10+c-'0', c=gc());
}
unordered_set<int> H;

int main() {
    freopen("hashuri.in", "r", stdin);
    freopen("hashuri.out", "w", stdout);

    int m, t, a;

    Read(m);
    while(m--) {
        Read(t); Read(a);
        if(t == 1) H.insert(a);
        if(t == 2) H.erase(a);
        if(t == 3) printf("%d\n", H.find(a) != H.end());
    }

    return 0;
}