n, m = map(int,input().split())
#l = [0] * n
#r = [0] * n
f = [False] * m
flag = 0

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

    for j in range(l, r+1):
        if f[j]:
            flag = 1
            break

    for j in range(m-1-r, m-1-l):
        if f[j]:
            flag = 2
            break

    if flag == 0:
        for j in range(l, r+1):
            f[j] = True
    if flag == 1:
        for j in range(m-1-r, m-1-l):
            f[j] = True
    if flag == 2:
        break

if flag == 2:
    print("NO")
else:
    print("YES")