#include <bits/stdc++.h>
using namespace std;
long long n,m,k;
pair<long long,long long> a[2145140];
void check()
{
	if(m<=2)
	{
		cout<<"Yes\n";
		return;
	}
	k=(a[2].second-a[1].second)/(a[2].first-a[1].first);
	if(k*(a[2].first-a[1].first)!=a[2].second-a[1].second)
	{
		cout<<"No\n";
		return;
	}
	for(int i=3;i<=m;i++)
	{
		if(k*(a[i].first-a[i-1].first)!=a[i].second-a[i-1].second)
		{
			cout<<"No\n";
			return;
		}
	}
	cout<<"Yes\n";
	return;
}
int main()
{
	long long t;
	cin>>t;
	long long k;
	while(t--)
	{
		cin>>n>>m;
		for(int i=1;i<=m;i++)
			cin>>a[i].first>>a[i].second;
		check();
	}
	return 0;
}