#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (int)(n); i ++)
#define irep(i,n) for (int i = (int)(n) - 1;i >= 0;--i)
using namespace std;
using ll = long long;
using PL = pair<ll,ll>;
using P = pair<int,int>;
constexpr int INF = 1000000000;
constexpr long long HINF = 1000000000000000;
constexpr long long MOD = 1000000007;// = 998244353;
constexpr double EPS = 1e-4;
constexpr double PI = 3.14159265358979;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int N,M; cin >> N >> M;
    vector<P> med(M);
    rep(i,M) {
        cin >> med[i].first >> med[i].second;
    }
    sort(med.begin(),med.end());

    int now = 0,t = 0;
    bool possible = true;
    rep(i,M) {
        if (med[i].first - t >= abs(med[i].second - now)) {
            t = med[i].first;
            now = med[i].second;
        } else {
            possible = false;
            break;
        }
    }
    cout << (possible ? "Yes" : "No") << '\n';
    return 0;
}