#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll=vector<long long>;
template<typename T>
T get(){T r;cin>>r;return r;}

int main() {
    ll n,m;
    bool f=true;
    cin>>n>>m;
    vector<pair<ll,ll>> tp(m);
    for(int i=0;i!=m;i++){
        tp[i].first=get<ll>();
        tp[i].second=get<ll>();

    }
    sort(tp.begin(),tp.end());
    if((tp[0].first==0&&tp[0].second!=0)||tp[0].second/tp[0].first>1){
        f=false;
    }
    for(ll i=0;f&&i!=m-1;i++){
        if((tp[i+1].second-tp[i].second)/(tp[i+1].first-tp[i].first)>1){
            break;
            f=false;
        }
    }
    if(f){
        cout<<"Yes"<<endl;
    }else{
        cout<<"No"<<endl;
    }
    


    system("pause");
}