#include<cstdio>
#include<map>
std::map<int,int> v;
int main()
{
 freopen("hashuri.in","r",stdin);
 freopen("hashuri.out","w",stdout);
 int n;
 scanf("%d ",&n);
 for(int i=1;i<=n;i++)
     {
      int op,param;
      scanf("%d %d ",&op,&param);
      switch(op)
             {
              case 1:
                     {
                      v[param]=1;
                      break;
                     };
              case 2:
                     {
                      v.erase(param);
                      break;
                     };
              case 3:
                     {
                      printf("%d\n",v.find(param)!=v.end());
                     };
             }
     }
 return 0;
}