#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<utility>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1'000'000'007; 

struct fast_io {
	fast_io(){
		std::cin.tie(nullptr);
		std::ios::sync_with_stdio(false);
	};
} fio;

#define T first
#define P second

signed main(){
	cout<<fixed<<setprecision(10);
	
    int N, M;
    vector<pair<int,int>> in;
    
    cin>>N>>M;
    
    in.resize(M+1);
    
    in[0].T = 0;
    in[0].P = 0;
    
    for(int i = 1; i <= M; i++){
        cin>>in[i].T>>in[i].P;
        
        if(i) {
               if(in[i].T - in[i-1].T < abs(in[i].P - in[i-1].P)) {
                   cout<<"No"<<endl;
                   return 0;
               }
        }
    }

cout<<"Yes"<<endl;
	
	
	
	return 0;
}