N,M=map(int,input().split())
A=[0]*M

for i in range(N):
    l,r=map(int,input().split())

    for j in range(l,r+1):
        A[min(j,M-1-j)]+=1

if M%2==0:
    if max(A)<=2:
        print("YES")
    else:
        print("NO")

else:
    if max(A)<=2 and A[M//2]<=1:
        print("YES")
    else:
        print("NO")