#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <cctype>
#include <numeric>
#include <cmath>

#define ll long long int
#define pb push_back
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
using namespace std;

int mx8[] = {0,0,1,-1,-1,1,-1,1};
int my8[] = {-1,1,0,0,-1,-1,1,1};
int mx4[] = {1,-1,0,0};
int my4[] = {0,0,-1,1};
const int MOD = 1000000007;


int main(){
    int n, m;
    cin >> n >> m;

    vector<ll> t(m),p(m);
    rep(i,m) {
        cin >> t[i] >> p[i];
        if(abs(p[i]) > n-1){
            cout << "No" << endl;
            return 0;
        }
    }

    if(t[0] < p[0]){
        cout << "No" << endl;
        return 0;
    }
    rep(i,m-1){
        if(t[i+1] -t[i] < abs(p[i+1]-p[i])){
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes" << endl;
}