#include<bits/stdc++.h>
#define MAXN 1010
using namespace std;
class Roadblock{
	public:
		int xx,yy;//行，列 
		int time;//时间 
};
const int fx[4]={0,0,1,-1};
const int fy[4]={1,-1,0,0};
int T,n;
int x[MAXN],y[MAXN];
bool a[MAXN][MAXN];
bool visit[MAXN][MAXN];
bool flag;
Roadblock fx1,fx2;
queue<Roadblock>q;
void BFS(int h,int l,int t)//行，列，时间 
{
	fx1.xx=h,fx1.yy=l,fx1.time=t;
	q.push(fx1);
	while(!q.empty())
	{
		fx1=q.front();
		q.pop();
		if(fx1.xx==n&&fx1.yy==n)
		{
			flag=1;
			break;
		}
		a[x[fx1.time-1]][y[fx1.time-1]]=1;
		for(int i=0;i<4;i++)
		{
			int dx=fx1.xx+fx[i];
			int dy=fx1.yy+fy[i];
			if(dx>=1&&dx<=n&&dy>=1&&dy<=n)
			{
				fx2.xx=dx,fx2.yy=dy,fx2.time=fx1.time+1;
				visit[dx][dy]=1;
				q.push(fx2);
			}
		}
	}
}
int main()
{
	cin>>T;
	while(T--)
	{
		cin>>n;
		memset(a,0,sizeof(a));
		memset(visit,0,sizeof(visit));
		flag=0;
		visit[1][1]=1;
		for(int i=1;i<=2*n-2;i++)
			cin>>x[i]>>y[i];
		BFS(1,1,0);
		if(flag==1) cout<<"Yes\n";
		else cout<<"No\n";
	}	
	return 0;
}

我MAXN即使开110还是有2个MLE