N,M=map(int,input().split())
H=[0]*(M+1)
for n in range(N):L,R=map(int,input().split());H[L]+=1;H[R+1]-=1;H[M-R-1]+=1;H[M-L]-=1
for h in H:
  n+=h
  if n>1+N:n+=1
print(['NO','YES'][n<N])