#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<math.h>
#include<map>
#include<iomanip>
#include<queue>

using namespace std;

int main(){
	
	long long n,m;
	cin >> n >> m;
	vector<pair<long long,long long>> pa(m+1);
	
	pa[0].first = pa[0].second = 0;
	
	for(int i=1;i<=m;i++){
		long long t,p;
		cin >> t >> p;
		pa[i].first=p;
		pa[i].second=t;
	}
	
	sort(pa.begin(),pa.end());
	
	for(int i=1;i<=m;i++){
		if(pa[i].first - pa[i-1].first > pa[i].second - pa[i-1].second){
			cout << "No" << endl;
			return 0;
		}
	}
	cout << "Yes" << endl;
	
	return 0;
}