#include<iostream>
#include<cstring>
using namespace std;

struct node
{
	int g;
	node *p;
};
int q;
node *head,*l,*n,*c;
int cz;
int x,y;

int main()
{
	cin>>q;
	head=new node;
	l=head;
	n=new node;
	n->g=1;
	n->p=NULL;
	head->p=n;
	l=n;
	for(int i=1;i<=q;i++)
	{
		n=head->p;
		cin>>cz;
		if(cz==1)
		{
			cin>>x>>y;
			while (n->g!=x)
			{
				n=n->p;
			}
			c=new node;
			c->p=n->p;
			n->p=c;
			c->g=y;
		}
		else if(cz==2)
		{
			cin>>x;
			while (n->g!=x)
			{
				n=n->p;
			}
			n=n->p;
			if(n->p==NULL) cout<<"0"<<endl;
			else cout<<n->g<<endl;
		}
		else if(cz==3)
		{
			cin>>x;
			while (n->g!=x)
			{
				n=n->p;
			}
			n=n->p->p;
		}
	}
	return 0;
}

大佬求救，不要题解，要问题所在