n, m = map(int, input().split())

LR = [tuple(map(int, input().split())) for _ in range(n)]

from atcoder.twosat import TwoSAT

ts = TwoSAT(n)

for i in range(n):
  l, r = LR[i]
  l_, r_ = m-1-r, m-1-l
  for j in range(i+1, n):
    ll, rr = LR[j]
    if not (r<ll or rr<l) and not (r_<ll or rr<l_):
      print('NO')
      exit()
    if not (r<ll or rr<l):
      ts.add_clause(i, 0, j, 0)
      ts.add_clause(i, 1, j, 1)
    elif not (r_<ll or rr<l_):
      ts.add_clause(i, 0, j, 1)
      ts.add_clause(i, 1, j, 0)
  
if ts.satisfiable():
  print('YES')
else:
  print('NO')