#include<set>
#include<stdio.h>
using namespace std;
FILE *f=fopen("heapuri.in","r");
FILE *g=fopen("heapuri.out","w");
using namespace std;
set<long> v;
int n,a,k=1,t[100010];
int main()
{
	fscanf(f,"%d",&n);
	for(int i=0;i<n;i++)
	{
		fscanf(f,"%d",&a);
		switch(a)
		{
		case 1:
			{
				fscanf(f,"%d",&a);
				t[k]=a;
				k++;
				v.insert(a);
				break;
			};
		case 2:
			{
				fscanf(f,"%d",&a);
				v.erase(t[a]);
				break;
			}
		case 3:
			{
				fprintf(g,"%ld",&v.begin());
				break;
			}
		}
	}
	return 0;
}