#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int N, M;
	cin >> N >> M;
	vector<ll> T(M), P(M);
	REP(i, M) scanf("%lld %lld", &T[i], &P[i]);
	vector<int> ord(M);
	iota(ALL(ord), 0);
	sort(ALL(ord), [&](int x, int y) { return T[x] < T[y]; });
	int pos = 0, last = 0;
	puts([&]() -> bool {
		for (auto i : ord) {
			if (abs(P[i] - pos) > T[i] - last) return false;
			last = T[i];
			pos = P[i];
		}
		return true;
	}() ? "Yes": "No");
}