inputs = lambda:map(int, raw_input().split())
n, m = inputs()
L = []
for i in xrange(n):
    l, r = inputs()
    L.append(min((l, r), (m-1-r, m-1-l)))
L.sort()
s = 0; t = m-1
for l, r in L:
    if t<s:
        print "NO"
        break
    if s<=l and r<=t:
        s = r+1
    elif s<=m-1-r and m-1-l<=t:
        t = m-1-r-1
    else:
        print "NO"
        break
else:
    print "YES"