#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;
    cin >> q;
    while(q--){
        int n, x[10], y[10];
        cin >> n;
        for (int i = 0; i < n; i++){
            cin >> x[i] >> y[i];
            
        }
        if (n <= 3)
            cout << "YES" << endl;
        else
            cout << "NO" << endl;
    }
    return 0;
}