n, m = map(int,input().split())
f = [False] * m
flag1 = 0
flag2 = 0

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

    for j in range(l, r+1):
        if f[j]:
            flag1 = 1
            break

    for j in range(m-1-r, m-l):
        if f[j]:
            flag2 = 1
            break

    if flag1 == 0 :
        for j in range(l, r+1):
            #print("0",j)
            f[j] = True
    elif flag2 == 0 :
        for j in range(m-1-r, m-l):
            #print("1",j)
            f[j] = True
    else:
        break

if flag1 + flag2 == 2:
    print("NO")
else:
    print("YES")