#include<stdio.h>
#include<map>
#include<string>
using namespace std;
map <int,char> a;
int main()
{
	freopen("hashuri.in","r",stdin);
	freopen("hashuri.out","w",stdout);
	int n;
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		int x,op;
		scanf("%d%d",&op,&x);
		if(op==1)
		{
			a[x]='0';
			continue;
		}
		if(op==2)
		{
			a.erase(x);
			continue;
		}
		if(op==3)
		{
			printf("%d\n",a[x]);
			continue;
		}
	}
	return 0;
}