#include #define rep(i,n) for (int i = 0; i < (n); ++i) #define printVec(v) printf("{"); for (const auto& i : v) { std::cout << i << ", "; } printf("}\n"); #define degreeToRadian(deg) (((deg)/360)*2*M_PI) #define radianTodegree(rad) (((rad)/2/M_PI)*360) template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; using P = pair; using ll = long long; const ll INF = 1LL<<60; const int MOD = 1e9 + 7; const int dx[4] = {1, 0, -1, 0}; const int dy[4] = {0, 1, 0, -1}; //cin.tie(0);ios::sync_with_stdio(false); //cout << fixed << setprecision(15) << y << endl; int main() { int N, M; cin >> N >> M; vector> inf; rep (i, M) { ll T, P; cin >> T >> P; inf.push_back({T, P}); } sort(inf.begin(), inf.end()); ll limit = 0; int current = 0; for (auto v : inf) { limit += abs(current - v.second); if (limit > v.first) { cout << "No" << endl; return 0; } current = v.second; } cout << "Yes" << endl; return 0; }