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):
  #print('tim:{} pos:{} t-tim:{} p:{}'.format(tim, pos, t-tim, p))
  if max(pos - p, p - pos) > t - tim:
    break
  else:
    tim = t
    pos = p
else:
  print('Yes')
  exit(0)

print('No')