#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    int q,n;
    cin>>q;
    for(int i=0;i<q;i++){
        cin>>n;
        long x[n];
        long y[n];
        for(int j=0;j<n;j++)
            cin>>x[j]>>y[j];
        
        if(n<4){
            cout<<"YES"<<endl;
        }
        else{
            cout<<"NO"<<endl;
        }
        
    }
    return 0;
}