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


int main() {
    short q;
    for(short z=0; z<q; z++)
    {
        short n;
        bool flag = true;
        int x[n], y[n];
        cin>>n;
        for(int i=0; i<n; i++)
            cin>>x[i]>>y[i];
        if(n<=3)
            cout<<"YES\n";
        if(n>=4)
            cout<<"NO\n";
    }
    return 0;
}