#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

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