#include<cstdio> 
#define ll long long
#define Mod 100003
using namespace std;
struct node
{
	int d;
	int k;
	node *nxt;
};
node *Insert(node *head,ll pos,int k);
node *Delete(node *head,ll pos);
node *Find(node *head,ll pos);
int main()
{
	int n,q;
	scanf("%d%d",&n,&q);
	node *head[100007]={};
	for (int i=1;i<=q;++i)
	{
		int b,x,y;
		scanf("%d%d%d",&b,&x,&y);
		ll pos=(ll)x*n+y;
		if (b==1)
		{
			int k;
			scanf("%d",&k);
			if (k)
				head[pos%Mod]=Insert(head[pos%Mod],pos,k);
			else
				head[pos%Mod]=Delete(head[pos%Mod],pos);
		}
		else
			printf("%d\n",Find(head[pos%Mod],pos)->k);
	}
	return 0;
}
node *Insert(node *head,ll pos,int k)
{
	int d=pos/Mod;
	node *p=head,*prev=NULL,*newp=new(node);
	newp->d=d;
	newp->k=k;
	while (p!=NULL){
		if (p->d>d)
			break;
		prev=p;
		p=p->nxt;
	}
	newp->nxt=p;
	if (prev==NULL)
		head=newp;
	else
		prev->nxt=newp;
	return head;
}
node *Delete(node *head,ll pos)
{
	int d=pos/Mod;
	node *p=head,*prev=NULL;
	while (p!=NULL){
		if (p->d==d)
			break;
		prev=p;
		p=p->nxt;
	}
	if (prev==NULL)
		head=head->nxt;
	else
		prev->nxt=p->nxt;
	delete p;
}
node *Find(node *head,ll pos){
	int d=pos/Mod;
	node *p=head,*prev=NULL;
	while (p!=NULL){
		if (p->d==d)
			break;
		prev=p;
		p=p->nxt;
	}
	return p;
}

大概是哈希（其实我也不懂哈希具体是什么）。