#include<cstdio>
#include<set>
#include<cctype>
#define BUF_SIZE 1 << 19
using namespace std;

set<int>s;
char buf[BUF_SIZE];
int n, pos = BUF_SIZE;

inline char getChar(FILE *fin) {
    if(pos == BUF_SIZE) {
        fread(buf,1,BUF_SIZE,fin);
        pos = 0;
    }
    return buf[pos++];
}

inline int read(FILE *fin) {
    int res = 0;
    char c;
    do {
        c = getChar(fin);
    }while(!isdigit(c));
    do {
        res = 10*res + c - '0';
        c = getChar(fin);
    }while(isdigit(c));
    return res;
}

int main() {
    int op, x;
    FILE *fin, *fout;
    fin = fopen("hashuri.in","r");
    fout = fopen("hashuri.out","w");
    n = read(fin);
    for(int i = 0; i < n; i++) {
        op = read(fin); x = read(fin);
        if(op == 1)
            s.insert(x);
        else if(op == 2)
            s.erase(x);
        else fprintf(fout,"%d\n",s.find(x) != s.end());
    }
    fclose(fin);
    fclose(fout);
    return 0;
}