#include <iostream>
//#include<atcoder/all>
#include <numeric>
#include <cmath>
#include <limits>
#include <stdio.h>
#include <iomanip>
#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>
//using namespace atcoder;
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<pair<ll, ll>>>;
vector<bool> seen;
bool C = true;
vector<ll> dist;
ll mod = 998244353;


int main() {

    ll N, M;
    cin >> N >> M;
    vll T(M+1), P(M+1);
    T[0] = 0; P[0] = 0;
    rep(i, M) {
        cin >> T[i + 1] >> P[i + 1];
    }
   // bool C = "Yes";
    rep(i, M) {
        if (T[i + 1] - T[i] < abs(P[i + 1] - P[i])) {
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes" << endl;
}