#include <bits/stdc++.h>
#define int long long
using namespace std;
int n, m, T, x[200005], p[200005];
signed main() {
	cin >> T;
	while (T--) {
		cin >> n >> m;
		for (int i = 1; i <= m; i++)
			cin >> p[i] >> x[i];
		if (m <= 1) {
			cout << "Yes" << endl;
		} else {
			double c = abs(x[1] - x[2]) * 1.0 / abs(p[1] - p[2]);
			if (c != (int)c) {
				cout << "No" << endl;
				continue;
			}
			int flag = 0;
			for (int i = 3; i <= m; i++) {
				double f = abs(x[i] - x[1]) * 1.0 / abs(p[i] - p[1]);
				if (f != (int)f || f != c) {
					cout << "No" << endl;
					flag = 1;
					break;
				}
			}
			if (!flag) {
				cout << "Yes" << endl;
			}
		}
	}
	return 0;
}

https://www.luogu.com.cn/record/171927901