#include<bits/stdc++.h>

using namespace std;

int main()
{
	int q,n;
	cin>>q;
    while(q--)
     {

        cin>>n;
        int point[n][2];
        for(int i=0;i<n;i++)
        {
            cin>>point[i][0]>>point[i][1];
        }

        if(n<4)
        {
            cout<<"YES"<<endl;
        }else {
            cout<<"NO"<<endl;

        }
    }
}