#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
int main() {
	long long n, m;
	cin >> n >> m;
	long long now = 0, now1 = 0;
	for (int i = 0; i < m; i++) {
		long long t, p;
		cin >> t >> p;
		long long t1 = t;
		t -= now;
		long long l = now1 - t;
		long long r = now1 + t;
		if (l > p || r < p) {
			cout << "No" << endl;
			return 0;
		}
		now = t1;
		now1 = p;
	}
	cout << "Yes" << endl;
	return 0;
}