N, M = map(int, input().split()) T = [] P = [] for i in range(M): t, p = map(int, input().split()) T.append(t) P.append(p) pos = 0 tim = 0 for t, p in zip(T, P): if max(pos - p, p - pos) >= t - tim: break else: tim = t pos = max(pos - p, p - pos) else: print('Yes') exit(0) print('No')